Logical Channel Configuration

ABSTRACT

A base station transmits, to a wireless device, a radio resource control (RRC) reconfiguration message comprising a first logical channel configuration for transmission of data of a first logical channel in an RRC connected state. The base station transmits, to the wireless device, an RRC release message comprising a second logical channel configuration for transmission of data of a second logical channel in an RRC inactive state or an RRC idle state, wherein the second logical channel configuration comprises an allowed configured grant list indicating that the data of the second logical channel is mapped to a configured grant configuration, of a configured grant, for transmission in the RRC inactive state or the RRC idle state. The base station receives, from the wireless device, the data of the second logical channel.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/851,988, filed Jun. 28, 2022, which is a continuation ofInternational Application No. PCT/US2021/065739, filed Dec. 30, 2021,which claims the benefit of U.S. Provisional Application No. 63/134,064,filed Jan. 5, 2021, all of which are hereby incorporated by reference intheir entireties.

BRIEF DESCRIPTION OF THE DRAWINGS

Examples of several of the various embodiments of the present disclosureare described herein with reference to the drawings.

FIG. 1A and FIG. 1B illustrate example mobile communication networks inwhich embodiments of the present disclosure may be implemented.

FIG. 2A and FIG. 2B respectively illustrate a New Radio (NR) user planeand control plane protocol stack.

FIG. 3 illustrates an example of services provided between protocollayers of the NR user plane protocol stack of FIG. 2A.

FIG. 4A illustrates an example downlink data flow through the NR userplane protocol stack of FIG. 2A.

FIG. 4B illustrates an example format of a MAC subheader in a MAC PDU.

FIG. 5A and FIG. 5B respectively illustrate a mapping between logicalchannels, transport channels, and physical channels for the downlink anduplink.

FIG. 6 is an example diagram showing RRC state transitions of a UE.

FIG. 7 illustrates an example configuration of an NR frame into whichOFDM symbols are grouped.

FIG. 8 illustrates an example configuration of a slot in the time andfrequency domain for an NR carrier.

FIG. 9 illustrates an example of bandwidth adaptation using threeconfigured BWPs for an NR carrier.

FIG. 10A illustrates three carrier aggregation configurations with twocomponent carriers.

FIG. 10B illustrates an example of how aggregated cells may beconfigured into one or more PUCCH groups.

FIG. 11A illustrates an example of an SS/PBCH block structure andlocation.

FIG. 11B illustrates an example of CSI-RSs that are mapped in the timeand frequency domains.

FIG. 12A and FIG. 12B respectively illustrate examples of three downlinkand uplink beam management procedures.

FIG. 13A, FIG. 13B, and FIG. 13C respectively illustrate a four-stepcontention-based random access procedure, a two-step contention-freerandom access procedure, and another two-step random access procedure.

FIG. 14A illustrates an example of CORESET configurations for abandwidth part.

FIG. 14B illustrates an example of a CCE-to-REG mapping for DCItransmission on a CORESET and PDCCH processing.

FIG. 15 illustrates an example of a wireless device in communicationwith a base station.

FIG. 16A, FIG. 16B, FIG. 16C, and FIG. 16D illustrate example structuresfor uplink and downlink transmission.

FIG. 17 illustrates an example of an RRC connection reestablishmentprocedure.

FIG. 18 illustrates an example of an RRC connection resume procedure.

FIG. 19 illustrates an example of small data transmission.

FIG. 20 illustrates an example of early data transmission (EDT).

FIG. 21 illustrates an example diagram of small data transmission usingpreconfigured uplink resource.

FIG. 22 illustrates an example of logical channel information for smalldata transmission.

FIG. 23 illustrates an example of logical channel information for smalldata transmission.

FIG. 24 illustrates an example of logical channel information for smalldata transmission in an RRC inactive state.

FIG. 25 illustrates an example of logical channel information for smalldata transmission in an RRC connected state.

FIG. 26 illustrates an example of logical channel information for smalldata transmission in a base station comprising CU (central unit) and DU(distributed unit).

FIG. 27 illustrates an first example of information of logical channelconfigured for small data transmission.

DETAILED DESCRIPTION

In the present disclosure, various embodiments are presented as examplesof how the disclosed techniques may be implemented and/or how thedisclosed techniques may be practiced in environments and scenarios. Itwill be apparent to persons skilled in the relevant art that variouschanges in form and detail can be made therein without departing fromthe scope. In fact, after reading the description, it will be apparentto one skilled in the relevant art how to implement alternativeembodiments. The present embodiments should not be limited by any of thedescribed exemplary embodiments. The embodiments of the presentdisclosure will be described with reference to the accompanyingdrawings. Limitations, features, and/or elements from the disclosedexample embodiments may be combined to create further embodiments withinthe scope of the disclosure. Any figures which highlight thefunctionality and advantages, are presented for example purposes only.The disclosed architecture is sufficiently flexible and configurable,such that it may be utilized in ways other than that shown. For example,the actions listed in any flowchart may be re-ordered or only optionallyused in some embodiments.

Embodiments may be configured to operate as needed. The disclosedmechanism may be performed when certain criteria are met, for example,in a wireless device, a base station, a radio environment, a network, acombination of the above, and/or the like. Example criteria may bebased, at least in part, on for example, wireless device or network nodeconfigurations, traffic load, initial system set up, packet sizes,traffic characteristics, a combination of the above, and/or the like.When the one or more criteria are met, various example embodiments maybe applied. Therefore, it may be possible to implement exampleembodiments that selectively implement disclosed protocols.

A base station may communicate with a mix of wireless devices. Wirelessdevices and/or base stations may support multiple technologies, and/ormultiple releases of the same technology. Wireless devices may have somespecific capability(ies) depending on wireless device category and/orcapability(ies). When this disclosure refers to a base stationcommunicating with a plurality of wireless devices, this disclosure mayrefer to a subset of the total wireless devices in a coverage area. Thisdisclosure may refer to, for example, a plurality of wireless devices ofa given LTE or 5G release with a given capability and in a given sectorof the base station. The plurality of wireless devices in thisdisclosure may refer to a selected plurality of wireless devices, and/ora subset of total wireless devices in a coverage area which performaccording to disclosed methods, and/or the like. There may be aplurality of base stations or a plurality of wireless devices in acoverage area that may not comply with the disclosed methods, forexample, those wireless devices or base stations may perform based onolder releases of LTE or 5G technology.

In this disclosure, “a” and “an” and similar phrases are to beinterpreted as “at least one” and “one or more.”

Similarly, any term that ends with the suffix “(s)” is to be interpretedas “at least one” and “one or more.” In this disclosure, the term “may”is to be interpreted as “may, for example.” In other words, the term“may” is indicative that the phrase following the term “may” is anexample of one of a multitude of suitable possibilities that may, or maynot, be employed by one or more of the various embodiments. The terms“comprises” and “consists of”, as used herein, enumerate one or morecomponents of the element being described. The term “comprises” isinterchangeable with “includes” and does not exclude unenumeratedcomponents from being included in the element being described. Bycontrast, “consists of” provides a complete enumeration of the one ormore components of the element being described. The term “based on”, asused herein, should be interpreted as “based at least in part on” ratherthan, for example, “based solely on”. The term “and/or” as used hereinrepresents any possible combination of enumerated elements. For example,“A, B, and/or C” may represent A; B; C; A and B; A and C; B and C; or A,B, and C.

If A and B are sets and every element of A is an element of B, A iscalled a subset of B. In this specification, only non-empty sets andsubsets are considered. For example, possible subsets of B={cell1,cell2} are: {cell1}, {cell2}, and {cell1, cell2}. The phrase “based on”(or equally “based at least on”) is indicative that the phrase followingthe term “based on” is an example of one of a multitude of suitablepossibilities that may, or may not, be employed to one or more of thevarious embodiments. The phrase “in response to” (or equally “inresponse at least to”) is indicative that the phrase following thephrase “in response to” is an example of one of a multitude of suitablepossibilities that may, or may not, be employed to one or more of thevarious embodiments. The phrase “depending on” (or equally “depending atleast to”) is indicative that the phrase following the phrase “dependingon” is an example of one of a multitude of suitable possibilities thatmay, or may not, be employed to one or more of the various embodiments.The phrase “employing/using” (or equally “employing/using at least”) isindicative that the phrase following the phrase “employing/using” is anexample of one of a multitude of suitable possibilities that may, or maynot, be employed to one or more of the various embodiments.

The term configured may relate to the capacity of a device whether thedevice is in an operational or non-operational state. Configured mayrefer to specific settings in a device that effect the operationalcharacteristics of the device whether the device is in an operational ornon-operational state. In other words, the hardware, software, firmware,registers, memory values, and/or the like may be “configured” within adevice, whether the device is in an operational or nonoperational state,to provide the device with specific characteristics. Terms such as “acontrol message to cause in a device” may mean that a control messagehas parameters that may be used to configure specific characteristics ormay be used to implement certain actions in the device, whether thedevice is in an operational or non-operational state.

In this disclosure, parameters (or equally called, fields, orInformation elements: IEs) may comprise one or more information objects,and an information object may comprise one or more other objects. Forexample, if parameter (IE) N comprises parameter (IE) M, and parameter(IE) M comprises parameter (IE) K, and parameter (IE) K comprisesparameter (information element) J. Then, for example, N comprises K, andN comprises J. In an example embodiment, when one or more messagescomprise a plurality of parameters, it implies that a parameter in theplurality of parameters is in at least one of the one or more messages,but does not have to be in each of the one or more messages.

Many features presented are described as being optional through the useof “may” or the use of parentheses.

For the sake of brevity and legibility, the present disclosure does notexplicitly recite each and every permutation that may be obtained bychoosing from the set of optional features. The present disclosure is tobe interpreted as explicitly disclosing all such permutations. Forexample, a system described as having three optional features may beembodied in seven ways, namely with just one of the three possiblefeatures, with any two of the three possible features or with three ofthe three possible features.

Many of the elements described in the disclosed embodiments may beimplemented as modules. A module is defined here as an element thatperforms a defined function and has a defined interface to otherelements. The modules described in this disclosure may be implemented inhardware, software in combination with hardware, firmware, wetware(e.g., hardware with a biological element) or a combination thereof,which may be behaviorally equivalent. For example, modules may beimplemented as a software routine written in a computer languageconfigured to be executed by a hardware machine (such as C, C++,Fortran, Java, Basic, Matlab or the like) or a modeling/simulationprogram such as Simulink, Stateflow, GNU Octave, or LabVIEWMathScript.It may be possible to implement modules using physical hardware thatincorporates discrete or programmable analog, digital and/or quantumhardware. Examples of programmable hardware comprise: computers,microcontrollers, microprocessors, application-specific integratedcircuits (ASICs); field programmable gate arrays (FPGAs); and complexprogrammable logic devices (CPLDs). Computers, microcontrollers andmicroprocessors are programmed using languages such as assembly, C, C++or the like. FPGAs, ASICs and CPLDs are often programmed using hardwaredescription languages (HDL) such as VHSIC hardware description language(VHDL) or Verilog that configure connections between internal hardwaremodules with lesser functionality on a programmable device. Thementioned technologies are often used in combination to achieve theresult of a functional module.

FIG. 1A illustrates an example of a mobile communication network 100 inwhich embodiments of the present disclosure may be implemented. Themobile communication network 100 may be, for example, a public landmobile network (PLMN) run by a network operator. As illustrated in FIG.1A, the mobile communication network 100 includes a core network (CN)102, a radio access network (RAN) 104, and a wireless device 106.

The CN 102 may provide the wireless device 106 with an interface to oneor more data networks (DNs), such as public DNs (e.g., the Internet),private DNs, and/or intra-operator DNs. As part of the interfacefunctionality, the CN 102 may set up end-to-end connections between thewireless device 106 and the one or more DNs, authenticate the wirelessdevice 106, and provide charging functionality.

The RAN 104 may connect the CN 102 to the wireless device 106 throughradio communications over an air interface. As part of the radiocommunications, the RAN 104 may provide scheduling, radio resourcemanagement, and retransmission protocols. The communication directionfrom the RAN 104 to the wireless device 106 over the air interface isknown as the downlink and the communication direction from the wirelessdevice 106 to the RAN 104 over the air interface is known as the uplink.Downlink transmissions may be separated from uplink transmissions usingfrequency division duplexing (FDD), time-division duplexing (TDD),and/or some combination of the two duplexing techniques.

The term wireless device may be used throughout this disclosure to referto and encompass any mobile device or fixed (non-mobile) device forwhich wireless communication is needed or usable. For example, awireless device may be a telephone, smart phone, tablet, computer,laptop, sensor, meter, wearable device, Internet of Things (loT) device,vehicle road side unit (RSU), relay node, automobile, and/or anycombination thereof. The term wireless device encompasses otherterminology, including user equipment (UE), user terminal (UT), accessterminal (AT), mobile station, handset, wireless transmit and receiveunit (WTRU), and/or wireless communication device.

The RAN 104 may include one or more base stations (not shown). The termbase station may be used throughout this disclosure to refer to andencompass a Node B (associated with UMTS and/or 3G standards), anEvolved Node B (eNB, associated with E-UTRA and/or 4G standards), aremote radio head (RRH), a baseband processing unit coupled to one ormore RRHs, a repeater node or relay node used to extend the coveragearea of a donor node, a Next Generation Evolved Node B (ng-eNB), aGeneration Node B (gNB, associated with NR and/or 5G standards), anaccess point (AP, associated with, for example, WiFi or any othersuitable wireless communication standard), and/or any combinationthereof. A base station may comprise at least one gNB Central Unit(gNB-CU) and at least one a gNB Distributed Unit (gNB-DU).

A base station included in the RAN 104 may include one or more sets ofantennas for communicating with the wireless device 106 over the airinterface. For example, one or more of the base stations may includethree sets of antennas to respectively control three cells (or sectors).The size of a cell may be determined by a range at which a receiver(e.g., a base station receiver) can successfully receive thetransmissions from a transmitter (e.g., a wireless device transmitter)operating in the cell. Together, the cells of the base stations mayprovide radio coverage to the wireless device 106 over a wide geographicarea to support wireless device mobility.

In addition to three-sector sites, other implementations of basestations are possible. For example, one or more of the base stations inthe RAN 104 may be implemented as a sectored site with more or less thanthree sectors. One or more of the base stations in the RAN 104 may beimplemented as an access point, as a baseband processing unit coupled toseveral remote radio heads (RRHs), and/or as a repeater or relay nodeused to extend the coverage area of a donor node. A baseband processingunit coupled to RRHs may be part of a centralized or cloud RANarchitecture, where the baseband processing unit may be eithercentralized in a pool of baseband processing units or virtualized. Arepeater node may amplify and rebroadcast a radio signal received from adonor node. A relay node may perform the same/similar functions as arepeater node but may decode the radio signal received from the donornode to remove noise before amplifying and rebroadcasting the radiosignal.

The RAN 104 may be deployed as a homogenous network of macrocell basestations that have similar antenna patterns and similar high-leveltransmit powers. The RAN 104 may be deployed as a heterogeneous network.In heterogeneous networks, small cell base stations may be used toprovide small coverage areas, for example, coverage areas that overlapwith the comparatively larger coverage areas provided by macrocell basestations. The small coverage areas may be provided in areas with highdata traffic (or so-called “hotspots”) or in areas with weak macrocellcoverage. Examples of small cell base stations include, in order ofdecreasing coverage area, microcell base stations, picocell basestations, and femtocell base stations or home base stations.

The Third-Generation Partnership Project (3GPP) was formed in 1998 toprovide global standardization of specifications for mobilecommunication networks similar to the mobile communication network 100in FIG. 1A. To date, 3GPP has produced specifications for threegenerations of mobile networks: a third generation (3G) network known asUniversal Mobile Telecommunications System (UMTS), a fourth generation(4G) network known as Long-Term Evolution (LTE), and a fifth generation(5G) network known as 5G System (5GS). Embodiments of the presentdisclosure are described with reference to the RAN of a 3GPP 5G network,referred to as next-generation RAN (NG-RAN). Embodiments may beapplicable to RANs of other mobile communication networks, such as theRAN 104 in FIG. 1A, the RANs of earlier 3G and 4G networks, and those offuture networks yet to be specified (e.g., a 3GPP 6G network). NG-RANimplements 5G radio access technology known as New Radio (NR) and may beprovisioned to implement 4G radio access technology or other radioaccess technologies, including non-3GPP radio access technologies.

FIG. 1B illustrates another example mobile communication network 150 inwhich embodiments of the present disclosure may be implemented. Mobilecommunication network 150 may be, for example, a PLMN run by a networkoperator. As illustrated in FIG. 1B, mobile communication network 150includes a 5G core network (5G-CN) 152, an NG-RAN 154, and UEs 156A and156B (collectively UEs 156). These components may be implemented andoperate in the same or similar manner as corresponding componentsdescribed with respect to FIG. 1A.

The 5G-CN 152 provides the UEs 156 with an interface to one or more DNs,such as public DNs (e.g., the Internet), private DNs, and/orintra-operator DNs. As part of the interface functionality, the 5G-CN152 may set up end-to-end connections between the UEs 156 and the one ormore DNs, authenticate the UEs 156, and provide charging functionality.Compared to the CN of a 3GPP 4G network, the basis of the 5G-CN 152 maybe a service-based architecture. This means that the architecture of thenodes making up the 5G-CN 152 may be defined as network functions thatoffer services via interfaces to other network functions. The networkfunctions of the 5G-CN 152 may be implemented in several ways, includingas network elements on dedicated or shared hardware, as softwareinstances running on dedicated or shared hardware, or as virtualizedfunctions instantiated on a platform (e.g., a cloud-based platform).

As illustrated in FIG. 1B, the 5G-CN 152 includes an Access and MobilityManagement Function (AMF) 158A and a User Plane Function (UPF) 158B,which are shown as one component AMF/UPF 158 in FIG. 1B for ease ofillustration. The UPF 158B may serve as a gateway between the NG-RAN 154and the one or more DNs. The UPF 158B may perform functions such aspacket routing and forwarding, packet inspection and user plane policyrule enforcement, traffic usage reporting, uplink classification tosupport routing of traffic flows to the one or more DNs, quality ofservice (QoS) handling for the user plane (e.g., packet filtering,gating, uplink/downlink rate enforcement, and uplink trafficverification), downlink packet buffering, and downlink data notificationtriggering. The UPF 158B may serve as an anchor point forintra-/inter-Radio Access Technology (RAT) mobility, an externalprotocol (or packet) data unit (PDU) session point of interconnect tothe one or more DNs, and/or a branching point to support a multi-homedPDU session. The UEs 156 may be configured to receive services through aPDU session, which is a logical connection between a UE and a DN.

The AMF 158A may perform functions such as Non-Access Stratum (NAS)signaling termination, NAS signaling security, Access Stratum (AS)security control, inter-ON node signaling for mobility between 3GPPaccess networks, idle mode UE reachability (e.g., control and executionof paging retransmission), registration area management, intra-systemand inter-system mobility support, access authentication, accessauthorization including checking of roaming rights, mobility managementcontrol (subscription and policies), network slicing support, and/orsession management function (SMF) selection. NAS may refer to thefunctionality operating between a CN and a UE, and AS may refer to thefunctionality operating between the UE and a RAN.

The 5G-CN 152 may include one or more additional network functions thatare not shown in FIG. 1B for the sake of clarity. For example, the 5G-CN152 may include one or more of a Session Management Function (SMF), anNR Repository Function (NRF), a Policy Control Function (PCF), a NetworkExposure Function (NEF), a Unified Data Management (UDM), an ApplicationFunction (AF), and/or an Authentication Server Function (AUSF).

The NG-RAN 154 may connect the 5G-CN 152 to the UEs 156 through radiocommunications over the air interface. The NG-RAN 154 may include one ormore gNBs, illustrated as gNB 160A and gNB 160B (collectively gNBs 160)and/or one or more ng-eNBs, illustrated as ng-eNB 162A and ng-eNB 162B(collectively ng-eNBs 162). The gNBs 160 and ng-eNBs 162 may be moregenerically referred to as base stations. The gNBs 160 and ng-eNBs 162may include one or more sets of antennas for communicating with the UEs156 over an air interface. For example, one or more of the gNBs 160and/or one or more of the ng-eNBs 162 may include three sets of antennasto respectively control three cells (or sectors). Together, the cells ofthe gNBs 160 and the ng-eNBs 162 may provide radio coverage to the UEs156 over a wide geographic area to support UE mobility.

As shown in FIG. 1B, the gNBs 160 and/or the ng-eNBs 162 may beconnected to the 5G-CN 152 by means of an NG interlace and to other basestations by an Xn interface. The NG and Xn interlaces may be establishedusing direct physical connections and/or indirect connections over anunderlying transport network, such as an internet protocol (IP)transport network. The gNBs 160 and/or the ng-eNBs 162 may be connectedto the UEs 156 by means of a Uu interlace. For example, as illustratedin FIG. 1B, gNB 160A may be connected to the UE 156A by means of a Uuinterlace. The NG, Xn, and Uu interlaces are associated with a protocolstack. The protocol stacks associated with the interfaces may be used bythe network elements in FIG. 1B to exchange data and signaling messagesand may include two planes: a user plane and a control plane. The userplane may handle data of interest to a user. The control plane mayhandle signaling messages of interest to the network elements.

The gNBs 160 and/or the ng-eNBs 162 may be connected to one or moreAMF/UPF functions of the 5G-CN 152, such as the AMF/UPF 158, by means ofone or more NG interlaces. For example, the gNB 160A may be connected tothe UPF 158B of the AMF/UPF 158 by means of an NG-User plane (NG-U)interlace. The NG-U interlace may provide delivery (e.g., non-guaranteeddelivery) of user plane PDUs between the gNB 160A and the UPF 158B. ThegNB 160A may be connected to the AMF 158A by means of an NG-Controlplane (NG-C) interlace. The NG-C interlace may provide, for example, NGinterlace management, UE context management, UE mobility management,transport of NAS messages, paging, PDU session management, andconfiguration transfer and/or warning message transmission.

The gNBs 160 may provide NR user plane and control plane protocolterminations towards the UEs 156 over the Uu interlace. For example, thegNB 160A may provide NR user plane and control plane protocolterminations toward the UE 156A over a Uu interlace associated with afirst protocol stack. The ng-eNBs 162 may provide Evolved UMTSTerrestrial Radio Access (E-UTRA) user plane and control plane protocolterminations towards the UEs 156 over a Uu interface, where E-UTRArefers to the 3GPP 4G radio-access technology. For example, the ng-eNB162B may provide E-UTRA user plane and control plane protocolterminations towards the UE 156B over a Uu interlace associated with asecond protocol stack.

The 5G-CN 152 was described as being configured to handle NR and 4Gradio accesses. It will be appreciated by one of ordinary skill in theart that it may be possible for NR to connect to a 4G core network in amode known as “non-standalone operation.” In non-standalone operation, a4G core network is used to provide (or at least support) control-planefunctionality (e.g., initial access, mobility, and paging). Althoughonly one AMF/UPF 158 is shown in FIG. 1B, one gNB or ng-eNB may beconnected to multiple AMF/UPF nodes to provide redundancy and/or to loadshare across the multiple AMF/UPF nodes.

As discussed, an interface (e.g., Uu, Xn, and NG interfaces) between thenetwork elements in FIG. 1B may be associated with a protocol stack thatthe network elements use to exchange data and signaling messages. Aprotocol stack may include two planes: a user plane and a control plane.The user plane may handle data of interest to a user, and the controlplane may handle signaling messages of interest to the network elements.

FIG. 2A and FIG. 2B respectively illustrate examples of NR user planeand NR control plane protocol stacks for the Uu interface that liesbetween a UE 210 and a gNB 220. The protocol stacks illustrated in FIG.2A and FIG. 2B may be the same or similar to those used for the Uuinterlace between, for example, the UE 156A and the gNB 160A shown inFIG. 1B.

FIG. 2A illustrates a NR user plane protocol stack comprising fivelayers implemented in the UE 210 and the gNB 220. At the bottom of theprotocol stack, physical layers (PHYs) 211 and 221 may provide transportservices to the higher layers of the protocol stack and may correspondto layer 1 of the Open Systems Interconnection (OSI) model. The nextfour protocols above PHYs 211 and 221 comprise media access controllayers (MACs) 212 and 222, radio link control layers (RLCs) 213 and 223,packet data convergence protocol layers (PDCPs) 214 and 224, and servicedata application protocol layers (SDAPs) 215 and 225. Together, thesefour protocols may make up layer 2 , or the data link layer, of the OSImodel.

FIG. 3 illustrates an example of services provided between protocollayers of the NR user plane protocol stack. Starting from the top ofFIG. 2A and FIG. 3 , the SDAPs 215 and 225 may perform QoS flowhandling. The UE 210 may receive services through a PDU session, whichmay be a logical connection between the UE 210 and a DN. The PDU sessionmay have one or more QoS flows. A UPF of a CN (e.g., the UPF 158B) maymap IP packets to the one or more QoS flows of the PDU session based onQoS requirements (e.g., in terms of delay, data rate, and/or errorrate). The SDAPs 215 and 225 may perform mapping/de-mapping between theone or more QoS flows and one or more data radio bearers. Themapping/de-mapping between the QoS flows and the data radio bearers maybe determined by the SDAP 225 at the gNB 220. The SDAP 215 at the UE 210may be informed of the mapping between the QoS flows and the data radiobearers through reflective mapping or control signaling received fromthe gNB 220. For reflective mapping, the SDAP 225 at the gNB 220 maymark the downlink packets with a QoS flow indicator (QFI), which may beobserved by the SDAP 215 at the UE 210 to determine themapping/de-mapping between the QoS flows and the data radio bearers.

The PDCPs 214 and 224 may perform header compression/decompression toreduce the amount of data that needs to be transmitted over the airinterlace, ciphering/deciphering to prevent unauthorized decoding ofdata transmitted over the air interlace, and integrity protection (toensure control messages originate from intended sources. The PDCPs 214and 224 may perform retransmissions of undelivered packets, in-sequencedelivery and reordering of packets, and removal of packets received induplicate due to, for example, an intra-gNB handover. The PDCPs 214 and224 may perform packet duplication to improve the likelihood of thepacket being received and, at the receiver, remove any duplicatepackets. Packet duplication may be useful for services that require highreliability.

Although not shown in FIG. 3 , PDCPs 214 and 224 may performmapping/de-mapping between a split radio bearer and RLC channels in adual connectivity scenario. Dual connectivity is a technique that allowsa UE to connect to two cells or, more generally, two cell groups: amaster cell group (MCG) and a secondary cell group (SCG). A split beareris when a single radio bearer, such as one of the radio bearers providedby the PDCPs 214 and 224 as a service to the SDAPs 215 and 225, ishandled by cell groups in dual connectivity. The PDCPs 214 and 224 maymap/de-map the split radio bearer between RLC channels belonging to cellgroups.

The RLCs 213 and 223 may perform segmentation, retransmission throughAutomatic Repeat Request

(ARQ), and removal of duplicate data units received from MACs 212 and222, respectively. The RLCs 213 and 223 may support three transmissionmodes: transparent mode (TM); unacknowledged mode (UM); and acknowledgedmode (AM). Based on the transmission mode an RLC is operating, the RLCmay perform one or more of the noted functions. The RLC configurationmay be per logical channel with no dependency on numerologies and/orTransmission Time Interval (TTI) durations. As shown in FIG. 3 , theRLCs 213 and 223 may provide RLC channels as a service to PDCPs 214 and224, respectively.

The MACs 212 and 222 may perform multiplexing/demultiplexing of logicalchannels and/or mapping between logical channels and transport channels.The multiplexing/demultiplexing may include multiplexing/demultiplexingof data units, belonging to the one or more logical channels, into/fromTransport Blocks (TBs) delivered to/from the PHYs 211 and 221. The MAC222 may be configured to perform scheduling, scheduling informationreporting, and priority handling between UEs by means of dynamicscheduling. Scheduling may be performed in the gNB 220 (at the MAC 222)for downlink and uplink. The MACs 212 and 222 may be configured toperform error correction through Hybrid Automatic Repeat Request (HARQ)(e.g., one HARQ entity per carrier in case of Carrier Aggregation (CA)),priority handling between logical channels of the UE 210 by means oflogical channel prioritization, and/or padding. The MACs 212 and 222 maysupport one or more numerologies and/or transmission timings. In anexample, mapping restrictions in a logical channel prioritization maycontrol which numerology and/or transmission timing a logical channelmay use. As shown in FIG. 3 , the MACs 212 and 222 may provide logicalchannels as a service to the RLCs 213 and 223.

The PHYs 211 and 221 may perform mapping of transport channels tophysical channels and digital and analog signal processing functions forsending and receiving information over the air interface. These digitaland analog signal processing functions may include, for example,coding/decoding and modulation/demodulation. The PHYs 211 and 221 mayperform multi-antenna mapping. As shown in FIG. 3 , the PHYs 211 and 221may provide one or more transport channels as a service to the MACs 212and 222.

FIG. 4A illustrates an example downlink data flow through the NR userplane protocol stack. FIG. 4A illustrates a downlink data flow of threeIP packets (n, n+1, and m) through the NR user plane protocol stack togenerate two TBs at the gNB 220. An uplink data flow through the NR userplane protocol stack may be similar to the downlink data flow depictedin FIG. 4A.

The downlink data flow of FIG. 4A begins when SDAP 225 receives thethree IP packets from one or more QoS flows and maps the three packetsto radio bearers. In FIG. 4A, the SDAP 225 maps IP packets n and n+1 toa first radio bearer 402 and maps IP packet m to a second radio bearer404. An SDAP header (labeled with an “H” in FIG. 4A) is added to an IPpacket. The data unit from/to a higher protocol layer is referred to asa service data unit (SDU) of the lower protocol layer and the data unitto/from a lower protocol layer is referred to as a protocol data unit(PDU) of the higher protocol layer. As shown in FIG. 4A, the data unitfrom the SDAP 225 is an SDU of lower protocol layer PDCP 224 and is aPDU of the SDAP 225.

The remaining protocol layers in FIG. 4A may perform their associatedfunctionality (e.g., with respect to FIG.

3), add corresponding headers, and forward their respective outputs tothe next lower layer. For example, the PDCP 224 may perform IP-headercompression and ciphering and forward its output to the RLC 223. The RLC223 may optionally perform segmentation (e.g., as shown for IP packet min FIG. 4A) and forward its output to the MAC 222. The MAC 222 maymultiplex a number of RLC PDUs and may attach a MAC subheader to an RLCPDU to form a transport block. In NR, the MAC subheaders may bedistributed across the MAC PDU, as illustrated in FIG. 4A. In LTE, theMAC subheaders may be entirely located at the beginning of the MAC PDU.The NR MAC PDU structure may reduce processing time and associatedlatency because the MAC PDU subheaders may be computed before the fullMAC PDU is assembled.

FIG. 4B illustrates an example format of a MAC subheader in a MAC PDU.The MAC subheader includes: an

SDU length field for indicating the length (e.g., in bytes) of the MACSDU to which the MAC subheader corresponds; a logical channel identifier(LCID) field for identifying the logical channel from which the MAC SDUoriginated to aid in the demultiplexing process; a flag (F) forindicating the size of the SDU length field; and a reserved bit (R)field for future use.

FIG. 4B further illustrates MAC control elements (CEs) inserted into theMAC PDU by a MAC, such as MAC 223 or MAC 222. For example, FIG. 4Billustrates two MAC CEs inserted into the MAC PDU. MAC CEs may beinserted at the beginning of a MAC PDU for downlink transmissions (asshown in FIG. 4B) and at the end of a MAC PDU for uplink transmissions.MAC CEs may be used for in-band control signaling. Example MAC CEsinclude: scheduling-related MAC CEs, such as buffer status reports andpower headroom reports; activation/deactivation MAC CEs, such as thosefor activation/deactivation of PDCP duplication detection, channel stateinformation (CSI) reporting, sounding reference signal (SRS)transmission, and prior configured components; discontinuous reception(DRX) related MAC CEs; timing advance MAC CEs; and random access relatedMAC CEs. A MAC CE may be preceded by a MAC subheader with a similarformat as described for MAC SDUs and may be identified with a reservedvalue in the LCID field that indicates the type of control informationincluded in the MAC CE.

Before describing the NR control plane protocol stack, logical channels,transport channels, and physical channels are first described as well asa mapping between the channel types. One or more of the channels may beused to carry out functions associated with the NR control planeprotocol stack described later below.

FIG. 5A and FIG. 5B illustrate, for downlink and uplink respectively, amapping between logical channels, transport channels, and physicalchannels. Information is passed through channels between the RLC, theMAC, and the PHY of the NR protocol stack. A logical channel may be usedbetween the RLC and the MAC and may be classified as a control channelthat carries control and configuration information in the NR controlplane or as a traffic channel that carries data in the NR user plane. Alogical channel may be classified as a dedicated logical channel that isdedicated to a specific UE or as a common logical channel that may beused by more than one UE. A logical channel may also be defined by thetype of information it carries. The set of logical channels defined byNR include, for example:

-   -   a paging control channel (PCCH) for carrying paging messages        used to page a UE whose location is not known to the network on        a cell level;    -   a broadcast control channel (BCCH) for carrying system        information messages in the form of a master information block        (MIB) and several system information blocks (SIBs), wherein the        system information messages may be used by the UEs to obtain        information about how a cell is configured and how to operate        within the cell;    -   a common control channel (CCCH) for carrying control messages        together with random access;    -   a dedicated control channel (DCCH) for carrying control messages        to/from a specific the UE to configure the UE; and    -   a dedicated traffic channel (DTCH) for carrying user data        to/from a specific the UE.

Transport channels are used between the MAC and PHY layers and may bedefined by how the information they carry is transmitted over the airinterface. The set of transport channels defined by NR include, forexample:

-   -   a paging channel (PCH) for carrying paging messages that        originated from the PCCH;    -   a broadcast channel (BCH) for carrying the MIB from the BCCH;    -   a downlink shared channel (DL-SCH) for carrying downlink data        and signaling messages, including the SIBs from the BCCH;    -   an uplink shared channel (UL-SCH) for carrying uplink data and        signaling messages; and    -   a random access channel (RACH) for allowing a UE to contact the        network without any prior scheduling.

The PHY may use physical channels to pass information between processinglevels of the PHY. A physical channel may have an associated set oftime-frequency resources for carrying the information of one or moretransport channels. The PHY may generate control information to supportthe low-level operation of the PHY and provide the control informationto the lower levels of the PHY via physical control channels, known asL1/L2 control channels. The set of physical channels and physicalcontrol channels defined by NR include, for example:

-   -   a physical broadcast channel (PBCH) for carrying the MIB from        the BCH;    -   a physical downlink shared channel (PDSCH) for carrying downlink        data and signaling messages from the DL-SCH, as well as paging        messages from the PCH;    -   a physical downlink control channel (PDCCH) for carrying        downlink control information (DCI), which may include downlink        scheduling commands, uplink scheduling grants, and uplink power        control commands;    -   a physical uplink shared channel (PUSCH) for carrying uplink        data and signaling messages from the UL-SCH and in some        instances uplink control information (UCI) as described below;    -   a physical uplink control channel (PUCCH) for carrying UCI,        which may include HARQ acknowledgments, channel quality        indicators (CQI), pre-coding matrix indicators (PMI), rank        indicators (RI), and scheduling requests (SR); and    -   a physical random access channel (PRACH) for random access.

Similar to the physical control channels, the physical layer generatesphysical signals to support the low-level operation of the physicallayer. As shown in FIG. 5A and FIG. 5B, the physical layer signalsdefined by NR include: primary synchronization signals (PSS), secondarysynchronization signals (SSS), channel state information referencesignals (CSI-RS), demodulation reference signals (DMRS), soundingreference signals (SRS), and phase-tracking reference signals (PT-RS).These physical layer signals will be described in greater detail below.

FIG. 2B illustrates an example NR control plane protocol stack. As shownin FIG. 2B, the NR control plane protocol stack may use the same/similarfirst four protocol layers as the example NR user plane protocol stack.These four protocol layers include the PHYs 211 and 221, the MACs 212and 222, the RLCs 213 and 223, and the PDCPs 214 and 224. Instead ofhaving the SDAPs 215 and 225 at the top of the stack as in the NR userplane protocol stack, the NR control plane stack has radio resourcecontrols (RRCs) 216 and 226 and NAS protocols 217 and 237 at the top ofthe NR control plane protocol stack.

The NAS protocols 217 and 237 may provide control plane functionalitybetween the UE 210 and the AMF 230 (e.g., the AMF 158A) or, moregenerally, between the UE 210 and the CN. The NAS protocols 217 and 237may provide control plane functionality between the UE 210 and the AMF230 via signaling messages, referred to as NAS messages. There is nodirect path between the UE 210 and the AMF 230 through which the NASmessages can be transported. The NAS messages may be transported usingthe AS of the Uu and NG interfaces. NAS protocols 217 and 237 mayprovide control plane functionality such as authentication, security,connection setup, mobility management, and session management.

The RRCs 216 and 226 may provide control plane functionality between theUE 210 and the gNB 220 or, more generally, between the UE 210 and theRAN. The RRCs 216 and 226 may provide control plane functionalitybetween the UE 210 and the gNB 220 via signaling messages, referred toas RRC messages. RRC messages may be transmitted between the UE 210 andthe RAN using signaling radio bearers and the same/similar PDCP, RLC,MAC, and PHY protocol layers. The MAC may multiplex control-plane anduser-plane data into the same transport block (TB). The RRCs 216 and 226may provide control plane functionality such as: broadcast of systeminformation related to AS and NAS; paging initiated by the CN or theRAN; establishment, maintenance and release of an RRC connection betweenthe UE 210 and the RAN; security functions including key management;establishment, configuration, maintenance and release of signaling radiobearers and data radio bearers; mobility functions; QoS managementfunctions; the UE measurement reporting and control of the reporting;detection of and recovery from radio link failure (RLF); and/or NASmessage transfer. As part of establishing an RRC connection, RRCs 216and 226 may establish an RRC context, which may involve configuringparameters for communication between the UE 210 and the RAN.

FIG. 6 is an example diagram showing RRC state transitions of a UE. TheUE may be the same or similar to the wireless device 106 depicted inFIG. 1A, the UE 210 depicted in FIG. 2A and FIG. 2B, or any otherwireless device described in the present disclosure. As illustrated inFIG. 6 , a UE may be in at least one of three RRC states: RRC connected602 (e.g., RRC_CONNECTED), RRC idle 604 (e.g., RRC_IDLE), and RRCinactive 606 (e.g., RRC_INACTIVE).

In RRC connected 602, the UE has an established RRC context and may haveat least one RRC connection with a base station. The base station may besimilar to one of the one or more base stations included in the RAN 104depicted in FIG. 1A, one of the gNBs 160 or ng-eNBs 162 depicted in FIG.1B, the gNB 220 depicted in FIG. 2A and FIG. 2B, or any other basestation described in the present disclosure. The base station with whichthe UE is connected may have the RRC context for the UE. The RRCcontext, referred to as the UE context, may comprise parameters forcommunication between the UE and the base station. These parameters mayinclude, for example: one or more AS contexts; one or more radio linkconfiguration parameters; bearer configuration information (e.g.,relating to a data radio bearer, signaling radio bearer, logicalchannel, QoS flow, and/or PDU session); security information; and/orPHY, MAC, RLC, PDCP, and/or SDAP layer configuration information. Whilein RRC connected 602, mobility of the UE may be managed by the RAN(e.g., the RAN 104 or the NG-RAN 154). The UE may measure the signallevels (e.g., reference signal levels) from a serving cell andneighboring cells and report these measurements to the base stationcurrently serving the UE. The UE's serving base station may request ahandover to a cell of one of the neighboring base stations based on thereported measurements. The RRC state may transition from RRC connected602 to RRC idle 604 through a connection release procedure 608 or to RRCinactive 606 through a connection inactivation procedure 610.

In RRC idle 604, an RRC context may not be established for the UE. InRRC idle 604, the UE may not have an RRC connection with the basestation. While in RRC idle 604, the UE may be in a sleep state for themajority of the time (e.g., to conserve battery power). The UE may wakeup periodically (e.g., once in every discontinuous reception cycle) tomonitor for paging messages from the RAN. Mobility of the UE may bemanaged by the UE through a procedure known as cell reselection. The RRCstate may transition from RRC idle 604 to RRC connected 602 through aconnection establishment procedure 612, which may involve a randomaccess procedure as discussed in greater detail below.

In RRC inactive 606, the RRC context previously established ismaintained in the UE and the base station. This allows for a fasttransition to RRC connected 602 with reduced signaling overhead ascompared to the transition from RRC idle 604 to RRC connected 602. Whilein RRC inactive 606, the UE may be in a sleep state and mobility of theUE may be managed by the UE through cell reselection. The RRC state maytransition from RRC inactive 606 to RRC connected 602 through aconnection resume procedure 614 or to RRC idle 604 though a connectionrelease procedure 616 that may be the same as or similar to connectionrelease procedure 608.

An RRC state may be associated with a mobility management mechanism. InRRC idle 604 and RRC inactive 606, mobility is managed by the UE throughcell reselection. The purpose of mobility management in RRC idle 604 andRRC inactive 606 is to allow the network to be able to notify the UE ofan event via a paging message without having to broadcast the pagingmessage over the entire mobile communications network. The mobilitymanagement mechanism used in RRC idle 604 and RRC inactive 606 may allowthe network to track the UE on a cell-group level so that the pagingmessage may be broadcast over the cells of the cell group that the UEcurrently resides within instead of the entire mobile communicationnetwork. The mobility management mechanisms for RRC idle 604 and RRCinactive 606 track the UE on a cell-group level. They may do so usingdifferent granularities of grouping. For example, there may be threelevels of cell-grouping granularity: individual cells; cells within aRAN area identified by a RAN area identifier (RAI); and cells within agroup of RAN areas, referred to as a tracking area and identified by atracking area identifier (TAI).

Tracking areas may be used to track the UE at the CN level. The CN(e.g., the CN 102 or the 5G-CN 152) may provide the UE with a list ofTAls associated with a UE registration area. If the UE moves, throughcell reselection, to a cell associated with a TAI not included in thelist of TAls associated with the UE registration area, the UE mayperform a registration update with the CN to allow the CN to update theUE's location and provide the UE with a new the UE registration area.

RAN areas may be used to track the UE at the RAN level. For a UE in RRCinactive 606 state, the UE may be assigned a RAN notification area. ARAN notification area may comprise one or more cell identities, a listof RAls, or a list of TAls. In an example, a base station may belong toone or more RAN notification areas. In an example, a cell may belong toone or more RAN notification areas. If the UE moves, through cellreselection, to a cell not included in the RAN notification areaassigned to the UE, the UE may perform a notification area update withthe RAN to update the UE's RAN notification area.

A base station storing an RRC context for a UE or a last serving basestation of the UE may be referred to as an anchor base station. Ananchor base station may maintain an RRC context for the UE at leastduring a period of time that the UE stays in a RAN notification area ofthe anchor base station and/or during a period of time that the UE staysin RRC inactive 606.

A gNB, such as gNBs 160 in FIG. 1B, may be split in two parts: a centralunit (gNB-CU), and one or more distributed units (gNB-DU). A gNB-CU maybe coupled to one or more gNB-DUs using an F1 interface. The gNB-CU maycomprise the RRC, the PDCP, and the SDAP. A gNB-DU may comprise the RLC,the MAC, and the PHY.

In NR, the physical signals and physical channels (discussed withrespect to FIG. 5A and FIG. 5B) may be mapped onto orthogonal frequencydivisional multiplexing (OFDM) symbols. OFDM is a multicarriercommunication scheme that transmits data over F orthogonal subcarriers(or tones). Before transmission, the data may be mapped to a series ofcomplex symbols (e.g., M-quadrature amplitude modulation (M-QAM) orM-phase shift keying (M-PSK) symbols), referred to as source symbols,and divided into F parallel symbol streams. The F parallel symbolstreams may be treated as though they are in the frequency domain andused as inputs to an Inverse Fast Fourier Transform (IFFT) block thattransforms them into the time domain. The IFFT block may take in Fsource symbols at a time, one from each of the F parallel symbolstreams, and use each source symbol to modulate the amplitude and phaseof one of F sinusoidal basis functions that correspond to the Forthogonal subcarriers. The output of the IFFT block may be Ftime-domain samples that represent the summation of the F orthogonalsubcarriers. The F time-domain samples may form a single OFDM symbol.After some processing (e.g., addition of a cyclic prefix) andup-conversion, an OFDM symbol provided by the IFFT block may betransmitted over the air interface on a carrier frequency. The Fparallel symbol streams may be mixed using an FFT block before beingprocessed by the IFFT block. This operation produces Discrete FourierTransform (DFT)-precoded OFDM symbols and may be used by UEs in theuplink to reduce the peak to average power ratio (PAPR). Inverseprocessing may be performed on the OFDM symbol at a receiver using anFFT block to recover the data mapped to the source symbols.

FIG. 7 illustrates an example configuration of an NR frame into whichOFDM symbols are grouped. An NR frame may be identified by a systemframe number (SFN). The SFN may repeat with a period of 1024 frames. Asillustrated, one NR frame may be 10 milliseconds (ms) in duration andmay include 10 subframes that are 1 ms in duration. A subframe may bedivided into slots that include, for example, 14 OFDM symbols per slot.

The duration of a slot may depend on the numerology used for the OFDMsymbols of the slot. In NR, a flexible numerology is supported toaccommodate different cell deployments (e.g., cells with carrierfrequencies below 1 GHz up to cells with carrier frequencies in themm-wave range). A numerology may be defined in terms of subcarrierspacing and cyclic prefix duration. For a numerology in NR, subcarrierspacings may be scaled up by powers of two from a baseline subcarrierspacing of 15 kHz, and cyclic prefix durations may be scaled down bypowers of two from a baseline cyclic prefix duration of 4.7 ps. Forexample, NR defines numerologies with the following subcarrierspacing/cyclic prefix duration combinations: 15 kHz/4.7 ps; 30 kHz/2.3ps; 60 kHz/1.2 ps; 120 kHz/0.59 ps; and 240 kHz/0.29 ps.

A slot may have a fixed number of OFDM symbols (e.g., 14 OFDM symbols).A numerology with a higher subcarrier spacing has a shorter slotduration and, correspondingly, more slots per subframe. FIG. 7illustrates this numerology-dependent slot duration andslots-per-subframe transmission structure (the numerology with asubcarrier spacing of 240 kHz is not shown in FIG. 7 for ease ofillustration). A subframe in NR may be used as a numerology-independenttime reference, while a slot may be used as the unit upon which uplinkand downlink transmissions are scheduled. To support low latency,scheduling in NR may be decoupled from the slot duration and start atany OFDM symbol and last for as many symbols as needed for atransmission. These partial slot transmissions may be referred to asmini-slot or subslot transmissions.

FIG. 8 illustrates an example configuration of a slot in the time andfrequency domain for an NR carrier. The slot includes resource elements(REs) and resource blocks (RBs). An RE is the smallest physical resourcein NR. An RE spans one OFDM symbol in the time domain by one subcarrierin the frequency domain as shown in FIG. 8 . An RB spans twelveconsecutive REs in the frequency domain as shown in FIG. 8 . An NRcarrier may be limited to a width of 275 RBs or 275×12=3300 subcarriers.Such a limitation, if used, may limit the NR carrier to 50, 100, 200,and 400 MHz for subcarrier spacings of 15, 30, 60, and 120 kHz,respectively, where the 400 MHz bandwidth may be set based on a 400 MHzper carrier bandwidth limit.

FIG. 8 illustrates a single numerology being used across the entirebandwidth of the NR carrier. In other example configurations, multiplenumerologies may be supported on the same carrier.

NR may support wide carrier bandwidths (e.g., up to 400 MHz for asubcarrier spacing of 120 kHz). Not all UEs may be able to receive thefull carrier bandwidth (e.g., due to hardware limitations). Also,receiving the full carrier bandwidth may be prohibitive in terms of UEpower consumption. In an example, to reduce power consumption and/or forother purposes, a UE may adapt the size of the UE's receive bandwidthbased on the amount of traffic the UE is scheduled to receive. This isreferred to as bandwidth adaptation.

NR defines bandwidth parts (BWPs) to support UEs not capable ofreceiving the full carrier bandwidth and to support bandwidthadaptation. In an example, a BWP may be defined by a subset ofcontiguous RBs on a carrier. A UE may be configured (e.g., via an RRClayer) with one or more downlink BWPs and one or more uplink BWPs perserving cell (e.g., up to four downlink BWPs and up to four uplink BWPsper serving cell). At a given time, one or more of the configured BWPsfor a serving cell may be active. These one or more BWPs may be referredto as active BWPs of the serving cell. When a serving cell is configuredwith a secondary uplink carrier, the serving cell may have one or morefirst active BWPs in the uplink carrier and one or more second activeBWPs in the secondary uplink carrier.

For unpaired spectra, a downlink BWP from a set of configured downlinkBWPs may be linked with an uplink

BWP from a set of configured uplink BWPs if a downlink BWP index of thedownlink BWP and an uplink BWP index of the uplink BWP are the same. Forunpaired spectra, a UE may expect that a center frequency for a downlinkBWP is the same as a center frequency for an uplink BWP.

For a downlink BWP in a set of configured downlink BWPs on a primarycell (PCell), a base station may configure a UE with one or more controlresource sets (CORESETs) for at least one search space. A search spaceis a set of locations in the time and frequency domains where the UE mayfind control information. The search space may be a UE-specific searchspace or a common search space (potentially usable by a plurality ofUEs). For example, a base station may configure a UE with a commonsearch space, on a PCell or on a primary secondary cell (PSCell), in anactive downlink BWP.

For an uplink BWP in a set of configured uplink BWPs, a BS may configurea UE with one or more resource sets for one or more PUCCH transmissions.A UE may receive downlink receptions (e.g., PDCCH or PDSCH) in adownlink BWP according to a configured numerology (e.g., subcarrierspacing and cyclic prefix duration) for the downlink BWP. The UE maytransmit uplink transmissions (e.g., PUCCH or PUSCH) in an uplink BWPaccording to a configured numerology (e.g., subcarrier spacing andcyclic prefix length for the uplink BWP).

One or more BWP indicator fields may be provided in Downlink ControlInformation (DCI). A value of a BWP indicator field may indicate whichBWP in a set of configured BWPs is an active downlink BWP for one ormore downlink receptions. The value of the one or more BWP indicatorfields may indicate an active uplink BWP for one or more uplinktransmissions.

A base station may semi-statically configure a UE with a defaultdownlink BWP within a set of configured downlink BWPs associated with aPCell. If the base station does not provide the default downlink BWP tothe UE, the default downlink BWP may be an initial active downlink BWP.The UE may determine which BWP is the initial active downlink BWP basedon a CORESET configuration obtained using the PBCH.

A base station may configure a UE with a BWP inactivity timer value fora PCell. The UE may start or restart a

BWP inactivity timer at any appropriate time. For example, the UE maystart or restart the BWP inactivity timer (a) when the UE detects a DCIindicating an active downlink BWP other than a default downlink BWP fora paired spectra operation; or (b) when a UE detects a DCI indicating anactive downlink BWP or active uplink BWP other than a default downlinkBWP or uplink BWP for an unpaired spectra operation. If the UE does notdetect DCI during an interval of time (e.g., 1 ms or 0.5 ms), the UE mayrun the BWP inactivity timer toward expiration (for example, incrementfrom zero to the BWP inactivity timer value, or decrement from the BWPinactivity timer value to zero). When the BWP inactivity timer expires,the UE may switch from the active downlink BWP to the default downlinkBWP.

In an example, a base station may semi-statically configure a UE withone or more BWPs. A UE may switch an active BWP from a first BWP to asecond BWP in response to receiving a DCI indicating the second BWP asan active BWP and/or in response to an expiry of the BWP inactivitytimer (e.g., if the second BWP is the default BWP).

Downlink and uplink BWP switching (where BWP switching refers toswitching from a currently active BWP to a not currently active BWP) maybe performed independently in paired spectra. In unpaired spectra,downlink and uplink BWP switching may be performed simultaneously.Switching between configured BWPs may occur based on RRC signaling, DCI,expiration of a BWP inactivity timer, and/or an initiation of randomaccess.

FIG. 9 illustrates an example of bandwidth adaptation using threeconfigured BWPs for an NR carrier. A UE configured with the three BWPsmay switch from one BWP to another BWP at a switching point. In theexample illustrated in FIG. 9 , the BWPs include: a BWP 902 with abandwidth of 40 MHz and a subcarrier spacing of 15 kHz; a BWP 904 with abandwidth of 10 MHz and a subcarrier spacing of 15 kHz; and a BWP 906with a bandwidth of 20 MHz and a subcarrier spacing of 60 kHz. The BWP902 may be an initial active BWP, and the BWP 904 may be a default BWP.The UE may switch between BWPs at switching points. In the example ofFIG. 9 , the UE may switch from the BWP 902 to the BWP 904 at aswitching point 908. The switching at the switching point 908 may occurfor any suitable reason, for example, in response to an expiry of a BWPinactivity timer (indicating switching to the default BWP) and/or inresponse to receiving a DCI indicating BWP 904 as the active BWP. The UEmay switch at a switching point 910 from active BWP 904 to BWP 906 inresponse receiving a DCI indicating BWP 906 as the active BWP. The UEmay switch at a switching point 912 from active BWP 906 to BWP 904 inresponse to an expiry of a BWP inactivity timer and/or in responsereceiving a DCI indicating BWP 904 as the active BWP. The UE may switchat a switching point 914 from active BWP 904 to BWP 902 in responsereceiving a DCI indicating BWP 902 as the active BWP.

If a UE is configured for a secondary cell with a default downlink BWPin a set of configured downlink BWPs and a timer value, UE proceduresfor switching BWPs on a secondary cell may be the same/similar as thoseon a primary cell. For example, the UE may use the timer value and thedefault downlink BWP for the secondary cell in the same/similar manneras the UE would use these values for a primary cell.

To provide for greater data rates, two or more carriers can beaggregated and simultaneously transmitted to/from the same UE usingcarrier aggregation (CA). The aggregated carriers in CA may be referredto as component carriers (CCs). When CA is used, there are a number ofserving cells for the UE, one for a CC. The CCs may have threeconfigurations in the frequency domain.

FIG. 10A illustrates the three CA configurations with two CCs. In theintraband, contiguous configuration 1002, the two CCs are aggregated inthe same frequency band (frequency band A) and are located directlyadjacent to each other within the frequency band. In the intraband,non-contiguous configuration 1004, the two CCs are aggregated in thesame frequency band (frequency band A) and are separated in thefrequency band by a gap. In the interband configuration 1006, the twoCCs are located in frequency bands (frequency band A and frequency bandB).

In an example, up to 32 CCs may be aggregated. The aggregated CCs mayhave the same or different bandwidths, subcarrier spacing, and/orduplexing schemes (TDD or FDD). A serving cell for a UE using CA mayhave a downlink CC. For FDD, one or more uplink CCs may be optionallyconfigured for a serving cell. The ability to aggregate more downlinkcarriers than uplink carriers may be useful, for example, when the UEhas more data traffic in the downlink than in the uplink.

When CA is used, one of the aggregated cells for a UE may be referred toas a primary cell (PCell). The PCell may be the serving cell that the UEinitially connects to at RRC connection establishment, reestablishment,and/or handover. The PCell may provide the UE with NAS mobilityinformation and the security input. UEs may have different PCells. Inthe downlink, the carrier corresponding to the PCell may be referred toas the downlink primary CC (DL PCC). In the uplink, the carriercorresponding to the PCell may be referred to as the uplink primary CC(UL PCC). The other aggregated cells for the UE may be referred to assecondary cells (SCells). In an example, the SCells may be configuredafter the PCell is configured for the UE. For example, an SCell may beconfigured through an RRC Connection Reconfiguration procedure. In thedownlink, the carrier corresponding to an SCell may be referred to as adownlink secondary CC (DL SCC). In the uplink, the carrier correspondingto the SCell may be referred to as the uplink secondary CC (UL SCC).

Configured SCells for a UE may be activated and deactivated based on,for example, traffic and channel conditions. Deactivation of an SCellmay mean that PDCCH and PDSCH reception on the SCell is stopped andPUSCH, SRS, and CQI transmissions on the SCell are stopped. ConfiguredSCells may be activated and deactivated using a MAC CE with respect toFIG. 4B. For example, a MAC CE may use a bitmap (e.g., one bit perSCell) to indicate which SCells (e.g., in a subset of configured SCells)for the UE are activated or deactivated. Configured SCells may bedeactivated in response to an expiration of an SCell deactivation timer(e.g., one SCell deactivation timer per SCell).

Downlink control information, such as scheduling assignments andscheduling grants, for a cell may be transmitted on the cellcorresponding to the assignments and grants, which is known asself-scheduling. The DCI for the cell may be transmitted on anothercell, which is known as cross-carrier scheduling. Uplink controlinformation (e.g., HARQ acknowledgments and channel state feedback, suchas CQI, PMI, and/or RI) for aggregated cells may be transmitted on thePUCCH of the PCell. For a larger number of aggregated downlink CCs, thePUCCH of the PCell may become overloaded. Cells may be divided intomultiple PUCCH groups.

FIG. 10B illustrates an example of how aggregated cells may beconfigured into one or more PUCCH groups. A PUCCH group 1010 and a PUCCHgroup 1050 may include one or more downlink CCs, respectively. In theexample of FIG. 10B, the PUCCH group 1010 includes three downlink CCs: aPCell 1011, an SCell 1012, and an SCell 1013. The PUCCH group 1050includes three downlink CCs in the present example: a PCell 1051, anSCell 1052, and an SCell 1053. One or more uplink CCs may be configuredas a PCell 1021, an SCell 1022, and an SCell 1023. One or more otheruplink CCs may be configured as a primary SCell (PSCell) 1061, an SCell1062, and an SCell 1063. Uplink control information (UCI) related to thedownlink CCs of the PUCCH group 1010, shown as UCI 1031, UCI 1032, andUCI 1033, may be transmitted in the uplink of the PCell 1021. Uplinkcontrol information (UCI) related to the downlink CCs of the PUCCH group1050, shown as UCI 1071, UCI 1072, and UCI 1073, may be transmitted inthe uplink of the PSCell 1061. In an example, if the aggregated cellsdepicted in FIG. 10B were not divided into the PUCCH group 1010 and thePUCCH group 1050, a single uplink PCell to transmit UCI relating to thedownlink CCs, and the PCell may become overloaded. By dividingtransmissions of UCI between the PCell 1021 and the PSCell 1061,overloading may be prevented.

A cell, comprising a downlink carrier and optionally an uplink carrier,may be assigned with a physical cell ID and a cell index. The physicalcell ID or the cell index may identify a downlink carrier and/or anuplink carrier of the cell, for example, depending on the context inwhich the physical cell ID is used. A physical cell ID may be determinedusing a synchronization signal transmitted on a downlink componentcarrier. A cell index may be determined using RRC messages. In thedisclosure, a physical cell ID may be referred to as a carrier ID, and acell index may be referred to as a carrier index. For example, when thedisclosure refers to a first physical cell ID for a first downlinkcarrier, the disclosure may mean the first physical cell ID is for acell comprising the first downlink carrier. The same/similar concept mayapply to, for example, a carrier activation. When the disclosureindicates that a first carrier is activated, the specification may meanthat a cell comprising the first carrier is activated.

In CA, a multi-carrier nature of a PHY may be exposed to a MAC. In anexample, a HARQ entity may operate on a serving cell. A transport blockmay be generated per assignment/grant per serving cell. A transportblock and potential HARQ retransmissions of the transport block may bemapped to a serving cell.

In the downlink, a base station may transmit (e.g., unicast, multicast,and/or broadcast) one or more Reference Signals (RSs) to a UE (e.g.,PSS, SSS, CSI-RS, DMRS, and/or PT-RS, as shown in FIG. 5A). In theuplink, the UE may transmit one or more RSs to the base station (e.g.,DMRS, PT-RS, and/or SRS, as shown in FIG. 5B). The PSS and the SSS maybe transmitted by the base station and used by the UE to synchronize theUE to the base station. The PSS and the SSS may be provided in asynchronization signal (SS)/physical broadcast channel (PBCH) block thatincludes the PSS, the SSS, and the PBCH. The base station mayperiodically transmit a burst of SS/PBCH blocks.

FIG. 11A illustrates an example of an SS/PBCH block's structure andlocation. A burst of SS/PBCH blocks may include one or more SS/PBCHblocks (e.g., 4 SS/PBCH blocks, as shown in FIG. 11A). Bursts may betransmitted periodically (e.g., every 2 frames or 20 5ms). A burst maybe restricted to a half-frame (e.g., a first half-frame having aduration of 5 ms). It will be understood that FIG. 11A is an example,and that these parameters (number of SS/PBCH blocks per burst,periodicity of bursts, position of burst within the frame) may beconfigured based on, for example: a carrier frequency of a cell in whichthe SS/PBCH block is transmitted; a numerology or subcarrier spacing ofthe cell; a configuration by the network (e.g., using RRC signaling); orany other suitable factor. In an example, the UE may assume a subcarrierspacing for the SS/PBCH block based on the carrier frequency beingmonitored, unless the radio network configured the UE to assume adifferent subcarrier spacing.

The SS/PBCH block may span one or more OFDM symbols in the time domain(e.g., 4 OFDM symbols, as shown in the example of FIG. 11A) and may spanone or more subcarriers in the frequency domain (e.g., 240 contiguoussubcarriers). The PSS, the SSS, and the PBCH may have a common centerfrequency. The PSS may be transmitted first and may span, for example, 1OFDM symbol and 127 subcarriers. The SSS may be transmitted after thePSS (e.g., two symbols later) and may span 1 OFDM symbol and 127subcarriers. The PBCH may be transmitted after the PSS (e.g., across thenext 3 OFDM symbols) and may span 240 subcarriers.

The location of the SS/PBCH block in the time and frequency domains maynot be known to the UE (e.g., if the UE is searching for the cell). Tofind and select the cell, the UE may monitor a carrier for the PSS. Forexample, the UE may monitor a frequency location within the carrier. Ifthe PSS is not found after a certain duration (e.g., 20 ms), the UE maysearch for the PSS at a different frequency location within the carrier,as indicated by a synchronization raster. If the PSS is found at alocation in the time and frequency domains, the UE may determine, basedon a known structure of the SS/PBCH block, the locations of the SSS andthe PBCH, respectively. The SS/PBCH block may be a cell-defining SSblock (CD-SSB). In an example, a primary cell may be associated with aCD-SSB. The CD-SSB may be located on a synchronization raster. In anexample, a cell selection/search and/or reselection may be based on theCD-SSB.

The SS/PBCH block may be used by the UE to determine one or moreparameters of the cell. For example, the UE may determine a physicalcell identifier (PCI) of the cell based on the sequences of the PSS andthe SSS, respectively. The UE may determine a location of a frameboundary of the cell based on the location of the SS/PBCH block. Forexample, the SS/PBCH block may indicate that it has been transmitted inaccordance with a transmission pattern, wherein a SS/PBCH block in thetransmission pattern is a known distance from the frame boundary.

The PBCH may use a QPSK modulation and may use forward error correction(FEC). The FEC may use polar coding. One or more symbols spanned by thePBCH may carry one or more DMRSs for demodulation of the PBCH. The PBCHmay include an indication of a current system frame number (SFN) of thecell and/or a SS/PBCH block timing index. These parameters mayfacilitate time synchronization of the UE to the base station. The PBCHmay include a master information block (MIB) used to provide the UE withone or more parameters. The MIB may be used by the UE to locateremaining minimum system information (RMSI) associated with the cell.The RMSI may include a System Information Block Type 1 (SIB1). The SIB1may contain information needed by the UE to access the cell. The UE mayuse one or more parameters of the MIB to monitor PDCCH, which may beused to schedule PDSCH. The PDSCH may include the SIB1. The SIB1 may bedecoded using parameters provided in the MIB. The PBCH may indicate anabsence of SIB1. Based on the PBCH indicating the absence of SIB1, theUE may be pointed to a frequency. The UE may search for an SS/PBCH blockat the frequency to which the UE is pointed.

The UE may assume that one or more SS/PBCH blocks transmitted with asame SS/PBCH block index are quasi co-located (QCLed) (e.g., having thesame/similar Doppler spread, Doppler shift, average gain, average delay,and/or spatial Rx parameters). The UE may not assume QCL for SS/PBCHblock transmissions having different SS/PBCH block indices.

SS/PBCH blocks (e.g., those within a half-frame) may be transmitted inspatial directions (e.g., using different beams that span a coveragearea of the cell). In an example, a first SS/PBCH block may betransmitted in a first spatial direction using a first beam, and asecond SS/PBCH block may be transmitted in a second spatial directionusing a second beam.

In an example, within a frequency span of a carrier, a base station maytransmit a plurality of SS/PBCH blocks. In an example, a first PCI of afirst SS/PBCH block of the plurality of SS/PBCH blocks may be differentfrom a second PCI of a second SS/PBCH block of the plurality of SS/PBCHblocks. The PCIs of SS/PBCH blocks transmitted in different frequencylocations may be different or the same.

The CSI-RS may be transmitted by the base station and used by the UE toacquire channel state information (CSI). The base station may configurethe UE with one or more CSI-RSs for channel estimation or any othersuitable purpose. The base station may configure a UE with one or moreof the same/similar CSI-RSs. The UE may measure the one or more CSI-RSs.The UE may estimate a downlink channel state and/or generate a CSIreport based on the measuring of the one or more downlink CSI-RSs. TheUE may provide the CSI report to the base station. The base station mayuse feedback provided by the UE (e.g., the estimated downlink channelstate) to perform link adaptation.

The base station may semi-statically configure the UE with one or moreCSI-RS resource sets. A CSI-RS resource may be associated with alocation in the time and frequency domains and a periodicity. The basestation may selectively activate and/or deactivate a CSI-RS resource.The base station may indicate to the UE that a CSI-RS resource in theCSI-RS resource set is activated and/or deactivated.

The base station may configure the UE to report CSI measurements. Thebase station may configure the UE to provide CSI reports periodically,aperiodically, or semi-persistently. For periodic CSI reporting, the UEmay be configured with a timing and/or periodicity of a plurality of CSIreports. For aperiodic CSI reporting, the base station may request a CSIreport. For example, the base station may command the UE to measure aconfigured CSI-RS resource and provide a CSI report relating to themeasurements. For semi-persistent CSI reporting, the base station mayconfigure the UE to transmit periodically, and selectively activate ordeactivate the periodic reporting. The base station may configure the UEwith a CSI-RS resource set and CSI reports using RRC signaling.

The CSI-RS configuration may comprise one or more parameters indicating,for example, up to 32 antenna ports. The UE may be configured to employthe same OFDM symbols for a downlink CSI-RS and a control resource set(CORESET) when the downlink CSI-RS and CORESET are spatially QCLed andresource elements associated with the downlink CSI-RS are outside of thephysical resource blocks (PRBs) configured for the CORESET. The UE maybe configured to employ the same OFDM symbols for downlink CSI-RS andSS/PBCH blocks when the downlink CSI-RS and SS/PBCH blocks are spatiallyQCLed and resource elements associated with the downlink CSI-RS areoutside of PRBs configured for the SS/PBCH blocks.

Downlink DMRSs may be transmitted by a base station and used by a UE forchannel estimation. For example, the downlink DMRS may be used forcoherent demodulation of one or more downlink physical channels (e.g.,PDSCH). An NR network may support one or more variable and/orconfigurable DMRS patterns for data demodulation. At least one downlinkDMRS configuration may support a front-loaded DMRS pattern. Afront-loaded DMRS may be mapped over one or more OFDM symbols (e.g., oneor two adjacent OFDM symbols). A base station may semi-staticallyconfigure the UE with a number (e.g., a maximum number) of front-loadedDMRS symbols for PDSCH. A DMRS configuration may support one or moreDMRS ports. For example, for single user-MIMO, a DMRS configuration maysupport up to eight orthogonal downlink DMRS ports per UE. Formultiuser-MIMO, a DMRS configuration may support up to 4 orthogonaldownlink DMRS ports per UE. A radio network may support (e.g., at leastfor CP-OFDM) a common DMRS structure for downlink and uplink, wherein aDMRS location, a DMRS pattern, and/or a scrambling sequence may be thesame or different. The base station may transmit a downlink DMRS and acorresponding PDSCH using the same precoding matrix. The UE may use theone or more downlink DMRSs for coherent demodulation/channel estimationof the PDSCH.

In an example, a transmitter (e.g., a base station) may use a precodermatrices for a part of a transmission bandwidth. For example, thetransmitter may use a first precoder matrix for a first bandwidth and asecond precoder matrix for a second bandwidth. The first precoder matrixand the second precoder matrix may be different based on the firstbandwidth being different from the second bandwidth. The UE may assumethat a same precoding matrix is used across a set of PRBs. The set ofPRBs may be denoted as a precoding resource block group (PRG).

A PDSCH may comprise one or more layers. The UE may assume that at leastone symbol with DMRS is present on a layer of the one or more layers ofthe PDSCH. A higher layer may configure up to 3 DMRSs for the PDSCH.

Downlink PT-RS may be transmitted by a base station and used by a UE forphase-noise compensation.

Whether a downlink PT-RS is present or not may depend on an RRCconfiguration. The presence and/or pattern of the downlink PT-RS may beconfigured on a UE-specific basis using a combination of RRC signalingand/or an association with one or more parameters employed for otherpurposes (e.g., modulation and coding scheme (MCS)), which may beindicated by DCI. When configured, a dynamic presence of a downlinkPT-RS may be associated with one or more DCI parameters comprising atleast MCS. An NR network may support a plurality of PT-RS densitiesdefined in the time and/or frequency domains. When present, a frequencydomain density may be associated with at least one configuration of ascheduled bandwidth. The UE may assume a same precoding for a DMRS portand a PT-RS port. A number of PT-RS ports may be fewer than a number ofDMRS ports in a scheduled resource. Downlink PT-RS may be confined inthe scheduled time/frequency duration for the UE. Downlink PT-RS may betransmitted on symbols to facilitate phase tracking at the receiver.

The UE may transmit an uplink DMRS to a base station for channelestimation. For example, the base station may use the uplink DMRS forcoherent demodulation of one or more uplink physical channels. Forexample, the UE may transmit an uplink DMRS with a PUSCH and/or a PUCCH.The uplink DM-RS may span a range of frequencies that is similar to arange of frequencies associated with the corresponding physical channel.The base station may configure the UE with one or more uplink DMRSconfigurations. At least one DMRS configuration may support afront-loaded DMRS pattern. The front-loaded DMRS may be mapped over oneor more OFDM symbols (e.g., one or two adjacent OFDM symbols). One ormore uplink DMRSs may be configured to transmit at one or more symbolsof a PUSCH and/or a PUCCH. The base station may semi-staticallyconfigure the UE with a number (e.g., maximum number) of front-loadedDMRS symbols for the PUSCH and/or the PUCCH, which the UE may use toschedule a single-symbol DMRS and/or a double-symbol DMRS. An NR networkmay support (e.g., for cyclic prefix orthogonal frequency divisionmultiplexing (CP-OFDM)) a common DMRS structure for downlink and uplink,wherein a DMRS location, a DMRS pattern, and/or a scrambling sequencefor the DMRS may be the same or different.

A PUSCH may comprise one or more layers, and the UE may transmit atleast one symbol with DMRS present on a layer of the one or more layersof the PUSCH. In an example, a higher layer may configure up to threeDMRSs for the PUSCH.

Uplink PT-RS (which may be used by a base station for phase trackingand/or phase-noise compensation) may or may not be present depending onan RRC configuration of the UE. The presence and/or pattern of uplinkPT-RS may be configured on a UE-specific basis by a combination of RRCsignaling and/or one or more parameters employed for other purposes(e.g., Modulation and Coding Scheme (MCS)), which may be indicated byDCI. When configured, a dynamic presence of uplink PT-RS may beassociated with one or more DCI parameters comprising at least MCS. Aradio network may support a plurality of uplink PT-RS densities definedin time/frequency domain. When present, a frequency domain density maybe associated with at least one configuration of a scheduled bandwidth.The UE may assume a same precoding for a DMRS port and a PT-RS port. Anumber of PT-RS ports may be fewer than a number of DMRS ports in ascheduled resource. For example, plink PT-RS may be confined in thescheduled time/frequency duration for the UE.

SRS may be transmitted by a UE to a base station for channel stateestimation to support uplink channel dependent scheduling and/or linkadaptation. SRS transmitted by the UE may allow a base station toestimate an uplink channel state at one or more frequencies. A schedulerat the base station may employ the estimated uplink channel state toassign one or more resource blocks for an uplink PUSCH transmission fromthe UE. The base station may semi-statically configure the UE with oneor more SRS resource sets. For an SRS resource set, the base station mayconfigure the UE with one or more SRS resources. An SRS resource setapplicability may be configured by a higher layer (e.g., RRC) parameter.For example, when a higher layer parameter indicates beam management, anSRS resource in a SRS resource set of the one or more SRS resource sets(e.g., with the same/similar time domain behavior, periodic, aperiodic,and/or the like) may be transmitted at a time instant (e.g.,simultaneously). The UE may transmit one or more SRS resources in SRSresource sets. An NR network may support aperiodic, periodic and/orsemi-persistent SRS transmissions. The UE may transmit SRS resourcesbased on one or more trigger types, wherein the one or more triggertypes may comprise higher layer signaling (e.g., RRC) and/or one or moreDCI formats. In an example, at least one DCI format may be employed forthe UE to select at least one of one or more configured SRS resourcesets. An SRS trigger type 0 may refer to an SRS triggered based on ahigher layer signaling. An SRS trigger type 1 may refer to an SRStriggered based on one or more DCI formats. In an example, when PUSCHand SRS are transmitted in a same slot, the UE may be configured totransmit SRS after a transmission of a PUSCH and a corresponding uplinkDMRS.

The base station may semi-statically configure the UE with one or moreSRS configuration parameters indicating at least one of following: a SRSresource configuration identifier; a number of SRS ports; time domainbehavior of an SRS resource configuration (e.g., an indication ofperiodic, semi-persistent, or aperiodic SRS); slot, mini-slot, and/orsubframe level periodicity; offset for a periodic and/or an aperiodicSRS resource; a number of OFDM symbols in an SRS resource; a startingOFDM symbol of an SRS resource; an SRS bandwidth; a frequency hoppingbandwidth; a cyclic shift; and/or an SRS sequence ID.

An antenna port is defined such that the channel over which a symbol onthe antenna port is conveyed can be inferred from the channel over whichanother symbol on the same antenna port is conveyed. If a first symboland a second symbol are transmitted on the same antenna port, thereceiver may infer the channel (e.g., fading gain, multipath delay,and/or the like) for conveying the second symbol on the antenna port,from the channel for conveying the first symbol on the antenna port. Afirst antenna port and a second antenna port may be referred to as quasico-located (QCLed) if one or more large-scale properties of the channelover which a first symbol on the first antenna port is conveyed may beinferred from the channel over which a second symbol on a second antennaport is conveyed. The one or more large-scale properties may comprise atleast one of: a delay spread; a Doppler spread; a Doppler shift; anaverage gain; an average delay; and/or spatial Receiving (Rx)parameters.

Channels that use beamforming require beam management. Beam managementmay comprise beam measurement, beam selection, and beam indication. Abeam may be associated with one or more reference signals. For example,a beam may be identified by one or more beamformed reference signals.The UE may perform downlink beam measurement based on downlink referencesignals (e.g., a channel state information reference signal (CSI-RS))and generate a beam measurement report. The UE may perform the downlinkbeam measurement procedure after an RRC connection is set up with a basestation.

FIG. 11B illustrates an example of channel state information referencesignals (CSI-RSs) that are mapped in the time and frequency domains. Asquare shown in FIG. 11B may span a resource block (RB) within abandwidth of a cell. A base station may transmit one or more RRCmessages comprising CSI-RS resource configuration parameters indicatingone or more CSI-RSs. One or more of the following parameters may beconfigured by higher layer signaling (e.g., RRC and/or MAC signaling)for a CSI-RS resource configuration: a CSI-RS resource configurationidentity, a number of CSI-RS ports, a CSI-RS configuration (e.g., symboland resource element (RE) locations in a subframe), a CSI-RS subframeconfiguration (e.g., subframe location, offset, and periodicity in aradio frame), a CSI-RS power parameter, a CSI-RS sequence parameter, acode division multiplexing (CDM) type parameter, a frequency density, atransmission comb, quasi co-location (QCL) parameters (e.g.,QCL-scramblingidentity, crs-portscount, mbsfn-subframeconfiglist,csi-rs-configZPid, qcl-csi-rs-configNZPid), and/or other radio resourceparameters.

The three beams illustrated in FIG. 11B may be configured for a UE in aUE-specific configuration. Three beams are illustrated in FIG. 11B (beam#1, beam #2, and beam #3), more or fewer beams may be configured. Beam#1 may be allocated with CSI-RS 1101 that may be transmitted in one ormore subcarriers in an RB of a first symbol. Beam #2 may be allocatedwith CSI-RS 1102 that may be transmitted in one or more subcarriers inan RB of a second symbol. Beam #3 may be allocated with CSI-RS 1103 thatmay be transmitted in one or more subcarriers in an RB of a thirdsymbol. By using frequency division multiplexing (FDM), a base stationmay use other subcarriers in a same RB (for example, those that are notused to transmit CSI-RS 1101) to transmit another CSI-RS associated witha beam for another UE. By using time domain multiplexing (TDM), beamsused for the UE may be configured such that beams for the UE use symbolsfrom beams of other UEs.

CSI-RSs such as those illustrated in FIG. 11B (e.g., CSI-RS 1101, 1102,1103) may be transmitted by the base station and used by the UE for oneor more measurements. For example, the UE may measure a reference signalreceived power (RSRP) of configured CSI-RS resources. The base stationmay configure the UE with a reporting configuration and the UE mayreport the RSRP measurements to a network (for example, via one or morebase stations) based on the reporting configuration. In an example, thebase station may determine, based on the reported measurement results,one or more transmission configuration indication (TCI) statescomprising a number of reference signals. In an example, the basestation may indicate one or more TCI states to the UE (e.g., via an RRCsignaling, a MAC CE, and/or a DCI). The UE may receive a downlinktransmission with a receive (Rx) beam determined based on the one ormore TCI states. In an example, the UE may or may not have a capabilityof beam correspondence. If the UE has the capability of beamcorrespondence, the UE may determine a spatial domain filter of atransmit (Tx) beam based on a spatial domain filter of the correspondingRx beam. If the UE does not have the capability of beam correspondence,the UE may perform an uplink beam selection procedure to determine thespatial domain filter of the Tx beam. The UE may perform the uplink beamselection procedure based on one or more sounding reference signal (SRS)resources configured to the UE by the base station. The base station mayselect and indicate uplink beams for the UE based on measurements of theone or more SRS resources transmitted by the UE.

In a beam management procedure, a UE may assess (e.g., measure) achannel quality of one or more beam pair links, a beam pair linkcomprising a transmitting beam transmitted by a base station and areceiving beam received by the UE. Based on the assessment, the UE maytransmit a beam measurement report indicating one or more beam pairquality parameters comprising, e.g., one or more beam identifications(e.g., a beam index, a reference signal index, or the like), RSRP, aprecoding matrix indicator (PMI), a channel quality indicator (CQI),and/or a rank indicator (RI).

FIG. 12A illustrates examples of three downlink beam managementprocedures: P1, P2, and P3. Procedure

P1 may enable a UE measurement on transmit (Tx) beams of a transmissionreception point (TRP) (or multiple TRPs), e.g., to support a selectionof one or more base station Tx beams and/or UE Rx beams (shown as ovalsin the top row and bottom row, respectively, of P1). Beamforming at aTRP may comprise a Tx beam sweep for a set of beams (shown, in the toprows of P1 and P2, as ovals rotated in a counter-clockwise directionindicated by the dashed arrow). Beamforming at a UE may comprise an Rxbeam sweep for a set of beams (shown, in the bottom rows of P1 and P3,as ovals rotated in a clockwise direction indicated by the dashedarrow). Procedure P2 may be used to enable a UE measurement on Tx beamsof a TRP (shown, in the top row of P2, as ovals rotated in acounter-clockwise direction indicated by the dashed arrow). The UEand/or the base station may perform procedure P2 using a smaller set ofbeams than is used in procedure P1, or using narrower beams than thebeams used in procedure P1. This may be referred to as beam refinement.The UE may perform procedure P3 for Rx beam determination by using thesame Tx beam at the base station and sweeping an Rx beam at the UE.

FIG. 12B illustrates examples of three uplink beam managementprocedures: U1, U2, and U3. Procedure U1 may be used to enable a basestation to perform a measurement on Tx beams of a UE, e.g., to support aselection of one or more UE Tx beams and/or base station Rx beams (shownas ovals in the top row and bottom row, respectively, of U1).Beamforming at the UE may include, e.g., a Tx beam sweep from a set ofbeams (shown in the bottom rows of U1 and U3 as ovals rotated in aclockwise direction indicated by the dashed arrow). Beamforming at thebase station may include, e.g., an Rx beam sweep from a set of beams(shown, in the top rows of U1 and U2, as ovals rotated in acounter-clockwise direction indicated by the dashed arrow). Procedure U2may be used to enable the base station to adjust its Rx beam when the UEuses a fixed Tx beam. The UE and/or the base station may performprocedure U2 using a smaller set of beams than is used in procedure P1,or using narrower beams than the beams used in procedure P1. This may bereferred to as beam refinement The UE may perform procedure U3 to adjustits Tx beam when the base station uses a fixed Rx beam.

A UE may initiate a beam failure recovery (BFR) procedure based ondetecting a beam failure. The UE may transmit a BFR request (e.g., apreamble, a UCI, an SR, a MAC CE, and/or the like) based on theinitiating of the BFR procedure. The UE may detect the beam failurebased on a determination that a quality of beam pair link(s) of anassociated control channel is unsatisfactory (e.g., having an error ratehigher than an error rate threshold, a received signal power lower thana received signal power threshold, an expiration of a timer, and/or thelike).

The UE may measure a quality of a beam pair link using one or morereference signals (RSs) comprising one or more SS/PBCH blocks, one ormore CSI-RS resources, and/or one or more demodulation reference signals(DMRSs). A quality of the beam pair link may be based on one or more ofa block error rate (BLER), an RSRP value, a signal to interference plusnoise ratio (SINR) value, a reference signal received quality (RSRQ)value, and/or a CSI value measured on RS resources. The base station mayindicate that an RS resource is quasi co-located (QCLed) with one ormore DM-RSs of a channel (e.g., a control channel, a shared datachannel, and/or the like). The RS resource and the one or more DMRSs ofthe channel may be QCLed when the channel characteristics (e.g., Dopplershift, Doppler spread, average delay, delay spread, spatial Rxparameter, fading, and/or the like) from a transmission via the RSresource to the UE are similar or the same as the channelcharacteristics from a transmission via the channel to the UE.

A network (e.g., a gNB and/or an ng-eNB of a network) and/or the UE mayinitiate a random access procedure. A UE in an RRC_IDLE state and/or anRRC_INACTIVE state may initiate the random access procedure to request aconnection setup to a network. The UE may initiate the random accessprocedure from an RRC_CONNECTED state. The UE may initiate the randomaccess procedure to request uplink resources (e.g., for uplinktransmission of an SR when there is no PUCCH resource available) and/oracquire uplink timing (e.g., when uplink synchronization status isnon-synchronized). The UE may initiate the random access procedure torequest one or more system information blocks (SIBs) (e.g., other systeminformation such as SIB2, SIB3, and/or the like). The UE may initiatethe random access procedure for a beam failure recovery request. Anetwork may initiate a random access procedure for a handover and/or forestablishing time alignment for an SCell addition.

FIG. 13A illustrates a four-step contention-based random accessprocedure. Prior to initiation of the procedure, a base station maytransmit a configuration message 1310 to the UE. The procedureillustrated in FIG. 13A comprises transmission of four messages: a Msg 11311, a Msg 2 1312, a Msg 3 1313, and a Msg 4 1314. The Msg 1 1311 mayinclude and/or be referred to as a preamble (or a random accesspreamble). The Msg 2 1312 may include and/or be referred to as a randomaccess response (RAR).

The configuration message 1310 may be transmitted, for example, usingone or more RRC messages. The one or more RRC messages may indicate oneor more random access channel (RACH) parameters to the UE. The one ormore RACH parameters may comprise at least one of following: generalparameters for one or more random access procedures (e.g.,RACH-configGeneral); cell-specific parameters (e.g., RACH-ConfigCommon);and/or dedicated parameters (e.g., RACH-configDedicated). The basestation may broadcast or multicast the one or more RRC messages to oneor more UEs. The one or more RRC messages may be UE-specific (e.g.,dedicated RRC messages transmitted to a UE in an RRC_CONNECTED stateand/or in an RRC_INACTIVE state). The UE may determine, based on the oneor more RACH parameters, a time-frequency resource and/or an uplinktransmit power for transmission of the Msg 1 1311 and/or the Msg 3 1313.Based on the one or more RACH parameters, the UE may determine areception timing and a downlink channel for receiving the Msg 2 1312 andthe Msg 4 1314.

The one or more RACH parameters provided in the configuration message1310 may indicate one or more Physical RACH (PRACH) occasions availablefor transmission of the Msg 1 1311. The one or more PRACH occasions maybe predefined. The one or more RACH parameters may indicate one or moreavailable sets of one or more PRACH occasions (e.g., prach-Configlndex).The one or more RACH parameters may indicate an association between (a)one or more PRACH occasions and (b) one or more reference signals. Theone or more RACH parameters may indicate an association between (a) oneor more preambles and (b) one or more reference signals. The one or morereference signals may be SS/PBCH blocks and/or CSI-RSs. For example, theone or more RACH parameters may indicate a number of SS/PBCH blocksmapped to a PRACH occasion and/or a number of preambles mapped to aSS/PBCH blocks.

The one or more RACH parameters provided in the configuration message1310 may be used to determine an uplink transmit power of Msg 1 1311and/or Msg 3 1313. For example, the one or more RACH parameters mayindicate a reference power for a preamble transmission (e.g., a receivedtarget power and/or an initial power of the preamble transmission).There may be one or more power offsets indicated by the one or more RACHparameters. For example, the one or more RACH parameters may indicate: apower ramping step; a power offset between SSB and CSI-RS; a poweroffset between transmissions of the Msg 1 1311 and the Msg 3 1313;and/or a power offset value between preamble groups. The one or moreRACH parameters may indicate one or more thresholds based on which theUE may determine at least one reference signal (e.g., an SSB and/orCSI-RS) and/or an uplink carrier (e.g., a normal uplink (NUL) carrierand/or a supplemental uplink (SUL) carrier).

The Msg 1 1311 may include one or more preamble transmissions (e.g., apreamble transmission and one or more preamble retransmissions). An RRCmessage may be used to configure one or more preamble groups (e.g.,group A and/or group B). A preamble group may comprise one or morepreambles. The UE may determine the preamble group based on a pathlossmeasurement and/or a size of the Msg 3 1313. The UE may measure an RSRPof one or more reference signals (e.g., SSBs and/or CSI-RSs) anddetermine at least one reference signal having an RSRP above an RSRPthreshold (e.g., rsrp-ThresholdSSB and/or rsrp-ThresholdCSl-RS). The UEmay select at least one preamble associated with the one or morereference signals and/or a selected preamble group, for example, if theassociation between the one or more preambles and the at least onereference signal is configured by an RRC message.

The UE may determine the preamble based on the one or more RACHparameters provided in the configuration message 1310. For example, theUE may determine the preamble based on a pathloss measurement, an RSRPmeasurement, and/or a size of the Msg 3 1313. As another example, theone or more RACH parameters may indicate: a preamble format; a maximumnumber of preamble transmissions; and/or one or more thresholds fordetermining one or more preamble groups (e.g., group A and group B). Abase station may use the one or more RACH parameters to configure the UEwith an association between one or more preambles and one or morereference signals (e.g., SSBs and/or CSI-RSs). If the association isconfigured, the UE may determine the preamble to include in Msg 1 1311based on the association. The Msg 1 1311 may be transmitted to the basestation via one or more PRACH occasions. The UE may use one or morereference signals (e.g., SSBs and/or CSI-RSs) for selection of thepreamble and for determining of the PRACH occasion. One or more RACHparameters (e.g., ra-ssb-OccasionMsklndex and/or ra-OccasionList) mayindicate an association between the PRACH occasions and the one or morereference signals.

The UE may perform a preamble retransmission if no response is receivedfollowing a preamble transmission. The UE may increase an uplinktransmit power for the preamble retransmission. The UE may select aninitial preamble transmit power based on a pathloss measurement and/or atarget received preamble power configured by the network. The UE maydetermine to retransmit a preamble and may ramp up the uplink transmitpower. The UE may receive one or more RACH parameters (e.g.,PREAMBLE_POWER_RAMPING_STEP) indicating a ramping step for the preambleretransmission. The ramping step may be an amount of incrementalincrease in uplink transmit power for a retransmission. The UE may rampup the uplink transmit power if the UE determines a reference signal(e.g., SSB and/or CSI-RS) that is the same as a previous preambletransmission. The UE may count a number of preamble transmissions and/orretransmissions (e.g., PREAMBLE_TRANSMISSION_COUNTER). The UE maydetermine that a random access procedure completed unsuccessfully, forexample, if the number of preamble transmissions exceeds a thresholdconfigured by the one or more RACH parameters (e.g., preambleTransMax).

The Msg 2 1312 received by the UE may include an RAR. In some scenarios,the Msg 2 1312 may include multiple RARs corresponding to multiple UEs.The Msg 2 1312 may be received after or in response to the transmittingof the Msg 1 1311. The Msg 2 1312 may be scheduled on the DL-SCH andindicated on a PDCCH using a random access RNTI (RA-RNTI). The Msg 21312 may indicate that the Msg 1 1311 was received by the base station.The Msg 2 1312 may include a time-alignment command that may be used bythe UE to adjust the UE's transmission timing, a scheduling grant fortransmission of the Msg 3 1313, and/or a Temporary Cell RNTI (TC-RNTI).After transmitting a preamble, the UE may start a time window (e.g.,ra-ResponseWindow) to monitor a PDCCH for the Msg 2 1312. The UE maydetermine when to start the time window based on a PRACH occasion thatthe UE uses to transmit the preamble. For example, the UE may start thetime window one or more symbols after a last symbol of the preamble(e.g., at a first PDCCH occasion from an end of a preambletransmission). The one or more symbols may be determined based on anumerology. The PDCCH may be in a common search space (e.g., aType1-PDCCH common search space) configured by an RRC message. The UEmay identify the RAR based on a Radio Network Temporary Identifier(RNTI). RNTIs may be used depending on one or more events initiating therandom access procedure. The UE may use random access RNTI (RA-RNTI).The RA-RNTI may be associated with PRACH occasions in which the UEtransmits a preamble. For example, the UE may determine the RA-RNTIbased on: an OFDM symbol index; a slot index; a frequency domain index;and/or a UL carrier indicator of the PRACH occasions. An example ofRA-RNTI may be as follows:

RA-RNTI=1+s_id+14×t_id+14×80×f_id+14×80×8×ul_carrier_id

where s_id may be an index of a first OFDM symbol of the PRACH occasion(e.g., 0≤s_id<14), t_id may be an index of a first slot of the PRACHoccasion in a system frame (e.g., 0≤t_id<80), f_id may be an index ofthe PRACH occasion in the frequency domain (e.g., 0≤f_id<8), andul_carrier_id may be a UL carrier used for a preamble transmission(e.g., 0 for an NUL carrier, and 1 for an SUL carrier). The UE maytransmit the Msg 3 1313 in response to a successful reception of the Msg2 1312 (e.g., using resources identified in the Msg 2 1312). The Msg 31313 may be used for contention resolution in, for example, thecontention-based random access procedure illustrated in FIG. 13A. Insome scenarios, a plurality of UEs may transmit a same preamble to abase station and the base station may provide an RAR that corresponds toa UE. Collisions may occur if the plurality of UEs interpret the RAR ascorresponding to themselves. Contention resolution (e.g., using the Msg3 1313 and the Msg 4 1314) may be used to increase the likelihood thatthe UE does not incorrectly use an identity of another the UE. Toperform contention resolution, the UE may include a device identifier inthe Msg 3 1313 (e.g., a C-RNTI if assigned, a TC-RNTI included in theMsg 2 1312, and/or any other suitable identifier).

The Msg 4 1314 may be received after or in response to the transmittingof the Msg 3 1313. If a C-RNTI was included in the Msg 3 1313, the basestation will address the UE on the PDCCH using the C-RNTI. If the UE'sunique C-RNTI is detected on the PDCCH, the random access procedure isdetermined to be successfully completed. If a TC-RNTI is included in theMsg 3 1313 (e.g., if the UE is in an RRC_IDLE state or not otherwiseconnected to the base station), Msg 4 1314 will be received using aDL-SCH associated with the TC-RNTI. If a MAC PDU is successfully decodedand a MAC PDU comprises the UE contention resolution identity MAC CEthat matches or otherwise corresponds with the CCCH SDU sent (e.g.,transmitted) in Msg 3 1313, the UE may determine that the contentionresolution is successful and/or the UE may determine that the randomaccess procedure is successfully completed.

The UE may be configured with a supplementary uplink (SUL) carrier and anormal uplink (NUL) carrier. An initial access (e.g., random accessprocedure) may be supported in an uplink carrier. For example, a basestation may configure the UE with two separate RACH configurations: onefor an SUL carrier and the other for an NUL carrier. For random accessin a cell configured with an SUL carrier, the network may indicate whichcarrier to use (NUL or SUL). The UE may determine the SUL carrier, forexample, if a measured quality of one or more reference signals is lowerthan a broadcast threshold. Uplink transmissions of the random accessprocedure (e.g., the Msg 1 1311 and/or the Msg 3 1313) may remain on theselected carrier. The UE may switch an uplink carrier during the randomaccess procedure (e.g., between the Msg 1 1311 and the Msg 3 1313) inone or more cases. For example, the UE may determine and/or switch anuplink carrier for the Msg 1 1311 and/or the Msg 3 1313 based on achannel clear assessment (e.g., a listen-before-talk).

FIG. 13B illustrates a two-step contention-free random access procedure.Similar to the four-step contention-based random access procedureillustrated in FIG. 13A, a base station may, prior to initiation of theprocedure, transmit a configuration message 1320 to the UE. Theconfiguration message 1320 may be analogous in some respects to theconfiguration message 1310. The procedure illustrated in FIG. 13Bcomprises transmission of two messages: a Msg 1 1321 and a Msg 2 1322.The Msg 1 1321 and the Msg 2 1322 may be analogous in some respects tothe Msg 1 1311 and a Msg 2 1312 illustrated in FIG. 13A, respectively.As will be understood from FIGS. 13A and 13B, the contention-free randomaccess procedure may not include messages analogous to the Msg 3 1313and/or the Msg 4 1314.

The contention-free random access procedure illustrated in FIG. 13B maybe initiated for a beam failure recovery, other SI request, SCelladdition, and/or handover. For example, a base station may indicate orassign to the UE the preamble to be used for the Msg 1 1321. The UE mayreceive, from the base station via PDCCH and/or RRC, an indication of apreamble (e.g., ra-Preamblelndex).

After transmitting a preamble, the UE may start a time window (e.g.,ra-ResponseWindow) to monitor a PDCCH for the RAR. In the event of abeam failure recovery request, the base station may configure the UEwith a separate time window and/or a separate PDCCH in a search spaceindicated by an RRC message (e.g., recoverySearchSpaceld). The UE maymonitor for a PDCCH transmission addressed to a Cell RNTI (C-RNTI) onthe search space. In the contention-free random access procedureillustrated in FIG. 13B, the UE may determine that a random accessprocedure successfully completes after or in response to transmission ofMsg 1 1321 and reception of a corresponding Msg 2 1322. The UE maydetermine that a random access procedure successfully completes, forexample, if a PDCCH transmission is addressed to a C-RNTI. The UE maydetermine that a random access procedure successfully completes, forexample, if the UE receives an RAR comprising a preamble identifiercorresponding to a preamble transmitted by the UE and/or the RARcomprises a MAC sub-PDU with the preamble identifier. The UE maydetermine the response as an indication of an acknowledgement for an SIrequest.

FIG. 13C illustrates another two-step random access procedure. Similarto the random access procedures illustrated in FIGS. 13A and 13B, a basestation may, prior to initiation of the procedure, transmit aconfiguration message 1330 to the UE. The configuration message 1330 maybe analogous in some respects to the configuration message 1310 and/orthe configuration message 1320. The procedure illustrated in FIG. 13Ccomprises transmission of two messages: a Msg A 1331 and a Msg B 1332.

Msg A 1331 may be transmitted in an uplink transmission by the UE. Msg A1331 may comprise one or more transmissions of a preamble 1341 and/orone or more transmissions of a transport block 1342. The transport block1342 may comprise contents that are similar and/or equivalent to thecontents of the Msg 3 1313 illustrated in FIG. 13A. The transport block1342 may comprise UCI (e.g., an SR, a HARQ ACK/NACK, and/or the like).The UE may receive the Msg B 1332 after or in response to transmittingthe Msg A 1331. The Msg B 1332 may comprise contents that are similarand/or equivalent to the contents of the Msg 2 1312 (e.g., an RAR)illustrated in FIGS. 13A and 13B and/or the Msg 4 1314 illustrated inFIG. 13A.

The UE may initiate the two-step random access procedure in FIG. 13C forlicensed spectrum and/or unlicensed spectrum. The UE may determine,based on one or more factors, whether to initiate the two-step randomaccess procedure. The one or more factors may be: a radio accesstechnology in use (e.g., LTE, NR, and/or the like); whether the UE hasvalid TA or not; a cell size; the UE's RRC state; a type of spectrum(e.g., licensed vs. unlicensed); and/or any other suitable factors.

The UE may determine, based on two-step RACH parameters included in theconfiguration message 1330, a radio resource and/or an uplink transmitpower for the preamble 1341 and/or the transport block 1342 included inthe Msg A 1331. The RACH parameters may indicate a modulation and codingschemes (MCS), a time-frequency resource, and/or a power control for thepreamble 1341 and/or the transport block 1342. A time-frequency resourcefor transmission of the preamble 1341 (e.g., a PRACH) and atime-frequency resource for transmission of the transport block 1342(e.g., a PUSCH) may be multiplexed using FDM, TDM, and/or CDM. The RACHparameters may enable the UE to determine a reception timing and adownlink channel for monitoring for and/or receiving Msg B 1332.

The transport block 1342 may comprise data (e.g., delay-sensitive data),an identifier of the UE, security information, and/or device information(e.g., an International Mobile Subscriber Identity (IMSI)). The basestation may transmit the Msg B 1332 as a response to the Msg A 1331. TheMsg B 1332 may comprise at least one of following: a preambleidentifier; a timing advance command; a power control command; an uplinkgrant (e.g., a radio resource assignment and/or an MCS); a UE identifierfor contention resolution; and/or an RNTI (e.g., a C-RNTI or a TC-RNTI).The UE may determine that the two-step random access procedure issuccessfully completed if: a preamble identifier in the Msg B 1332 ismatched to a preamble transmitted by the UE; and/or the identifier ofthe UE in Msg B 1332 is matched to the identifier of the UE in the Msg A1331 (e.g., the transport block 1342).

A UE and a base station may exchange control signaling. The controlsignaling may be referred to as L1/L2 control signaling and mayoriginate from the PHY layer (e.g., layer 1) and/or the MAC layer (e.g.,layer 2). The control signaling may comprise downlink control signalingtransmitted from the base station to the UE and/or uplink controlsignaling transmitted from the UE to the base station.

The downlink control signaling may comprise: a downlink schedulingassignment; an uplink scheduling grant indicating uplink radio resourcesand/or a transport format; a slot format information; a preemptionindication; a power control command; and/or any other suitablesignaling. The UE may receive the downlink control signaling in apayload transmitted by the base station on a physical downlink controlchannel (PDCCH). The payload transmitted on the PDCCH may be referred toas downlink control information (DCI). In some scenarios, the PDCCH maybe a group common PDCCH (GC-PDCCH) that is common to a group of UEs.

A base station may attach one or more cyclic redundancy check (CRC)parity bits to a DCI in order to facilitate detection of transmissionerrors. When the DCI is intended for a UE (or a group of the UEs), thebase station may scramble the CRC parity bits with an identifier of theUE (or an identifier of the group of the UEs). Scrambling the CRC paritybits with the identifier may comprise Modulo-2 addition (or an exclusiveOR operation) of the identifier value and the CRC parity bits. Theidentifier may comprise a 16-bit value of a radio network temporaryidentifier (RNTI).

DCIs may be used for different purposes. A purpose may be indicated bythe type of RNTI used to scramble the CRC parity bits. For example, aDCI having CRC parity bits scrambled with a paging RNTI (P-RNTI) mayindicate paging information and/or a system information changenotification. The P-RNTI may be predefined as “FFFE” in hexadecimal. ADCI having CRC parity bits scrambled with a system information RNTI(SI-RNTI) may indicate a broadcast transmission of the systeminformation. The SI-RNTI may be predefined as “FFFF” in hexadecimal. ADCI having CRC parity bits scrambled with a random access RNTI (RA-RNTI)may indicate a random access response (RAR). A DCI having CRC paritybits scrambled with a cell RNTI (C-RNTI) may indicate a dynamicallyscheduled unicast transmission and/or a triggering of PDCCH-orderedrandom access. A DCI having CRC parity bits scrambled with a temporarycell RNTI (TC-RNTI) may indicate a contention resolution (e.g., a Msg 3analogous to the Msg 3 1313 illustrated in FIG. 13A). Other RNTIsconfigured to the UE by a base station may comprise a ConfiguredScheduling RNTI (CS-RNTI), a Transmit Power Control-PUCCH RNTI(TPC-PUCCH-RNTI), a Transmit Power Control-PUSCH RNTI (TPC-PUSCH-RNTI),a Transmit Power Control-SRS RNTI (TPC-SRS-RNTI), an Interruption RNTI(INT-RNTI), a Slot Format Indication RNTI (SFI-RNTI), a Semi-PersistentCSI RNTI (SP-CSI-RNTI), a Modulation and Coding Scheme Cell RNTI(MCS-C-RNTI), and/or the like.

Depending on the purpose and/or content of a DCI, the base station maytransmit the DCIs with one or more

DCI formats. For example, DCI format 0_0 may be used for scheduling ofPUSCH in a cell. DCI format 0_0 may be a fallback DCI format (e.g., withcompact DCI payloads). DCI format 0_1 may be used for scheduling ofPUSCH in a cell (e.g., with more DCI payloads than DCI format 0_0). DCIformat 1_0 may be used for scheduling of PDSCH in a cell. DCI format 1_0may be a fallback DCI format (e.g., with compact DCI payloads). DCIformat 1_1 may be used for scheduling of PDSCH in a cell (e.g., withmore DCI payloads than DCI format 1_0). DCI format 2_0 may be used forproviding a slot format indication to a group of UEs. DCI format 2_1 maybe used for notifying a group of UEs of a physical resource block and/orOFDM symbol where the UE may assume no transmission is intended to theUE. DCI format 2_2 may be used for transmission of a transmit powercontrol (TPC) command for PUCCH or PUSCH. DCI format 2_3 may be used fortransmission of a group of TPC commands for SRS transmissions by one ormore UEs. DCI format(s) for new functions may be defined in futurereleases. DCI formats may have different DCI sizes, or may share thesame DCI size.

After scrambling a DCI with a RNTI, the base station may process the DCIwith channel coding (e.g., polar coding), rate matching, scramblingand/or QPSK modulation. A base station may map the coded and modulatedDCI on resource elements used and/or configured for a PDCCH. Based on apayload size of the DCI and/or a coverage of the base station, the basestation may transmit the DCI via a PDCCH occupying a number ofcontiguous control channel elements (CCEs). The number of the contiguousCCEs (referred to as aggregation level) may be 1, 2, 4, 8, 16, and/orany other suitable number. A CCE may comprise a number (e.g., 6) ofresource-element groups (REGs). A REG may comprise a resource block inan OFDM symbol. The mapping of the coded and modulated DCI on theresource elements may be based on mapping of CCEs and REGs (e.g.,CCE-to-REG mapping).

FIG. 14A illustrates an example of CORESET configurations for abandwidth part. The base station may transmit a DCI via a PDCCH on oneor more control resource sets (CORESETs). A CORESET may comprise atime-frequency resource in which the UE tries to decode a DCI using oneor more search spaces. The base station may configure a CORESET in thetime-frequency domain. In the example of FIG. 14A, a first CORESET 1401and a second CORESET 1402 occur at the first symbol in a slot. The firstCORESET 1401 overlaps with the second CORESET 1402 in the frequencydomain. A third CORESET 1403 occurs at a third symbol in the slot. Afourth CORESET 1404 occurs at the seventh symbol in the slot. CORESETsmay have a different number of resource blocks in frequency domain.

FIG. 14B illustrates an example of a CCE-to-REG mapping for DCItransmission on a CORESET and PDCCH processing. The CCE-to-REG mappingmay be an interleaved mapping (e.g., for the purpose of providingfrequency diversity) or a non-interleaved mapping (e.g., for thepurposes of facilitating interference coordination and/orfrequency-selective transmission of control channels). The base stationmay perform different or same CCE-to-REG mapping on different CORESETs.A CORESET may be associated with a CCE-to-REG mapping by RRCconfiguration. A CORESET may be configured with an antenna port quasico-location (QCL) parameter. The antenna port QCL parameter may indicateQCL information of a demodulation reference signal (DMRS) for PDCCHreception in the CORESET.

The base station may transmit, to the UE, RRC messages comprisingconfiguration parameters of one or more CORESETs and one or more searchspace sets. The configuration parameters may indicate an associationbetween a search space set and a CORESET. A search space set maycomprise a set of PDCCH candidates formed by CCEs at a given aggregationlevel. The configuration parameters may indicate: a number of PDCCHcandidates to be monitored per aggregation level; a PDCCH monitoringperiodicity and a PDCCH monitoring pattern; one or more DCI formats tobe monitored by the UE; and/or whether a search space set is a commonsearch space set or a UE-specific search space set. A set of CCEs in thecommon search space set may be predefined and known to the UE. A set ofCCEs in the UE-specific search space set may be configured based on theUE's identity (e.g., C-RNTI).

As shown in FIG. 14B, the UE may determine a time-frequency resource fora CORESET based on RRC messages. The UE may determine a CCE-to-REGmapping (e.g., interleaved or non-interleaved, and/or mappingparameters) for the CORESET based on configuration parameters of theCORESET. The UE may determine a number (e.g., at most 10) of searchspace sets configured on the CORESET based on the RRC messages. The UEmay monitor a set of PDCCH candidates according to configurationparameters of a search space set. The UE may monitor a set of PDCCHcandidates in one or more CORESETs for detecting one or more DCIs.Monitoring may comprise decoding one or more PDCCH candidates of the setof the PDCCH candidates according to the monitored DCI formats.Monitoring may comprise decoding a DCI content of one or more PDCCHcandidates with possible (or configured) PDCCH locations, possible (orconfigured) PDCCH formats (e.g., number of CCEs, number of PDCCHcandidates in common search spaces, and/or number of PDCCH candidates inthe UE-specific search spaces) and possible (or configured) DCI formats.The decoding may be referred to as blind decoding. The UE may determinea DCI as valid for the UE, in response to CRC checking (e.g., scrambledbits for CRC parity bits of the DCI matching a RNTI value). The UE mayprocess information contained in the DCI (e.g., a scheduling assignment,an uplink grant, power control, a slot format indication, a downlinkpreemption, and/or the like).

The UE may transmit uplink control signaling (e.g., uplink controlinformation (UCI)) to a base station. The uplink control signaling maycomprise hybrid automatic repeat request (HARQ) acknowledgements forreceived DL-SCH transport blocks. The UE may transmit the HARQacknowledgements after receiving a DL-SCH transport block. Uplinkcontrol signaling may comprise channel state information (CSI)indicating channel quality of a physical downlink channel. The UE maytransmit the CSI to the base station. The base station, based on thereceived CSI, may determine transmission format parameters (e.g.,comprising multi-antenna and beamforming schemes) for a downlinktransmission. Uplink control signaling may comprise scheduling requests(SR). The UE may transmit an SR indicating that uplink data is availablefor transmission to the base station. The UE may transmit a UCI (e.g.,HARQ acknowledgements (HARQ-ACK), CSI report, SR, and the like) via aphysical uplink control channel (PUCCH) or a physical uplink sharedchannel (PUCCH). The UE may transmit the uplink control signaling via aPUCCH using one of several PUCCH formats.

There may be five PUCCH formats and the UE may determine a PUCCH formatbased on a size of the UCI (e.g., a number of uplink symbols of UCItransmission and a number of UCI bits). PUCCH format 0 may have a lengthof one or two OFDM symbols and may include two or fewer bits. The UE maytransmit UCI in a PUCCH resource using PUCCH format 0 if thetransmission is over one or two symbols and the number of HARQ-ACKinformation bits with positive or negative SR (HARQ-ACK/SR bits) is oneor two. PUCCH format 1 may occupy a number between four and fourteenOFDM symbols and may include two or fewer bits. The UE may use PUCCHformat 1 if the transmission is four or more symbols and the number ofHARQ-ACK/SR bits is one or two. PUCCH format 2 may occupy one or twoOFDM symbols and may include more than two bits. The UE may use PUCCHformat 2 if the transmission is over one or two symbols and the numberof UCI bits is two or more. PUCCH format 3 may occupy a number betweenfour and fourteen OFDM symbols and may include more than two bits. TheUE may use PUCCH format 3 if the transmission is four or more symbols,the number of UCI bits is two or more and PUCCH resource does notinclude an orthogonal cover code. PUCCH format 4 may occupy a numberbetween four and fourteen OFDM symbols and may include more than twobits. The UE may use PUCCH format 4 if the transmission is four or moresymbols, the number of UCI bits is two or more and the PUCCH resourceincludes an orthogonal cover code.

The base station may transmit configuration parameters to the UE for aplurality of PUCCH resource sets using, for example, an RRC message. Theplurality of PUCCH resource sets (e.g., up to four sets) may beconfigured on an uplink BWP of a cell. A PUCCH resource set may beconfigured with a PUCCH resource set index, a plurality of PUCCHresources with a PUCCH resource being identified by a PUCCH resourceidentifier (e.g., pucch-Resourceid), and/or a number (e.g., a maximumnumber) of UCI information bits the UE may transmit using one of theplurality of PUCCH resources in the PUCCH resource set. When configuredwith a plurality of PUCCH resource sets, the UE may select one of theplurality of PUCCH resource sets based on a total bit length of the UCIinformation bits (e.g., HARQ-ACK, SR, and/or CSI). If the total bitlength of UCI information bits is two or fewer, the UE may select afirst PUCCH resource set having a PUCCH resource set index equal to “0”.If the total bit length of UCI information bits is greater than two andless than or equal to a first configured value, the UE may select asecond PUCCH resource set having a PUCCH resource set index equal to“1”. If the total bit length of UCI information bits is greater than thefirst configured value and less than or equal to a second configuredvalue, the UE may select a third PUCCH resource set having a PUCCHresource set index equal to “2”. If the total bit length of UCIinformation bits is greater than the second configured value and lessthan or equal to a third value (e.g., 1406), the UE may select a fourthPUCCH resource set having a PUCCH resource set index equal to “3”.

After determining a PUCCH resource set from a plurality of PUCCHresource sets, the UE may determine a

PUCCH resource from the PUCCH resource set for UCI (HARQ-ACK, CSI,and/or SR) transmission. The UE may determine the PUCCH resource basedon a PUCCH resource indicator in a DCI (e.g., with a DCI format 1_0 orDCI for 1_1) received on a PDCCH. A three-bit PUCCH resource indicatorin the DCI may indicate one of eight PUCCH resources in the PUCCHresource set. Based on the PUCCH resource indicator, the UE may transmitthe UCI (HARQ-ACK, CSI and/or SR) using a PUCCH resource indicated bythe PUCCH resource indicator in the DCI.

FIG. 15 illustrates an example of a wireless device 1502 incommunication with a base station 1504 in accordance with embodiments ofthe present disclosure. The wireless device 1502 and base station 1504may be part of a mobile communication network, such as the mobilecommunication network 100 illustrated in FIG. 1A, the mobilecommunication network 150 illustrated in FIG. 1B, or any othercommunication network. Only one wireless device 1502 and one basestation 1504 are illustrated in FIG. 15 , but it will be understood thata mobile communication network may include more than one UE and/or morethan one base station, with the same or similar configuration as thoseshown in FIG. 15 .

The base station 1504 may connect the wireless device 1502 to a corenetwork (not shown) through radio communications over the air interface(or radio interface) 1506. The communication direction from the basestation 1504 to the wireless device 1502 over the air interface 1506 isknown as the downlink, and the communication direction from the wirelessdevice 1502 to the base station 1504 over the air interface is known asthe uplink. Downlink transmissions may be separated from uplinktransmissions using FDD, TDD, and/or some combination of the twoduplexing techniques.

In the downlink, data to be sent to the wireless device 1502 from thebase station 1504 may be provided to the processing system 1508 of thebase station 1504. The data may be provided to the processing system1508 by, for example, a core network. In the uplink, data to be sent tothe base station 1504 from the wireless device 1502 may be provided tothe processing system 1518 of the wireless device 1502. The processingsystem 1508 and the processing system 1518 may implement layer 3 andlayer 2 OSI functionality to process the data for transmission. Layer 2may include an SDAP layer, a PDCP layer, an RLC layer, and a MAC layer,for example, with respect to FIG. 2A, FIG. 2B, FIG. 3 , and FIG. 4A.Layer 3 may include an RRC layer as with respect to FIG. 2B.

After being processed by processing system 1508, the data to be sent tothe wireless device 1502 may be provided to a transmission processingsystem 1510 of base station 1504. Similarly, after being processed bythe processing system 1518, the data to be sent to base station 1504 maybe provided to a transmission processing system 1520 of the wirelessdevice 1502. The transmission processing system 1510 and thetransmission processing system 1520 may implement layer 1 OSIfunctionality. Layer 1 may include a PHY layer with respect to FIG. 2A,FIG. 2B, FIG. 3 , and FIG. 4A. For transmit processing, the PHY layermay perform, for example, forward error correction coding of transportchannels, interleaving, rate matching, mapping of transport channels tophysical channels, modulation of physical channel, multiple-inputmultiple-output (MIMO) or multi-antenna processing, and/or the like.

At the base station 1504, a reception processing system 1512 may receivethe uplink transmission from the wireless device 1502. At the wirelessdevice 1502, a reception processing system 1522 may receive the downlinktransmission from base station 1504. The reception processing system1512 and the reception processing system 1522 may implement layer 1 OSIfunctionality. Layer 1 may include a PHY layer with respect to FIG. 2A,FIG. 2B, FIG. 3 , and FIG. 4A. For receive processing, the PHY layer mayperform, for example, error detection, forward error correctiondecoding, deinterleaving, demapping of transport channels to physicalchannels, demodulation of physical channels, MIMO or multi-antennaprocessing, and/or the like.

As shown in FIG. 15 , a wireless device 1502 and the base station 1504may include multiple antennas. The multiple antennas may be used toperform one or more MIMO or multi-antenna techniques, such as spatialmultiplexing (e.g., single-user MIMO or multi-user MIMO),transmit/receive diversity, and/or beamforming. In other examples, thewireless device 1502 and/or the base station 1504 may have a singleantenna.

The processing system 1508 and the processing system 1518 may beassociated with a memory 1514 and a memory 1524, respectively. Memory1514 and memory 1524 (e.g., one or more non-transitory computer readablemediums) may store computer program instructions or code that may beexecuted by the processing system 1508 and/or the processing system 1518to carry out one or more of the functionalities discussed in the presentapplication. Although not shown in FIG. 15 , the transmission processingsystem 1510, the transmission processing system 1520, the receptionprocessing system 1512, and/or the reception processing system 1522 maybe coupled to a memory (e.g., one or more non-transitory computerreadable mediums) storing computer program instructions or code that maybe executed to carry out one or more of their respectivefunctionalities.

The processing system 1508 and/or the processing system 1518 maycomprise one or more controllers and/or one or more processors. The oneor more controllers and/or one or more processors may comprise, forexample, a general-purpose processor, a digital signal processor (DSP),a microcontroller, an application specific integrated circuit (ASIC), afield programmable gate array (FPGA) and/or other programmable logicdevice, discrete gate and/or transistor logic, discrete hardwarecomponents, an on-board unit, or any combination thereof. The processingsystem 1508 and/or the processing system 1518 may perform at least oneof signal coding/processing, data processing, power control,input/output processing, and/or any other functionality that may enablethe wireless device 1502 and the base station 1504 to operate in awireless environment.

The processing system 1508 and/or the processing system 1518 may beconnected to one or more peripherals 1516 and one or more peripherals1526, respectively. The one or more peripherals 1516 and the one or moreperipherals 1526 may include software and/or hardware that providefeatures and/or functionalities, for example, a speaker, a microphone, akeypad, a display, a touchpad, a power source, a satellite transceiver,a universal serial bus (USB) port, a hands-free headset, a frequencymodulated (FM) radio unit, a media player, an Internet browser, anelectronic control unit (e.g., for a motor vehicle), and/or one or moresensors (e.g., an accelerometer, a gyroscope, a temperature sensor, aradar sensor, a lidar sensor, an ultrasonic sensor, a light sensor, acamera, and/or the like). The processing system 1508 and/or theprocessing system 1518 may receive user input data from and/or provideuser output data to the one or more peripherals 1516 and/or the one ormore peripherals 1526. The processing system 1518 in the wireless device1502 may receive power from a power source and/or may be configured todistribute the power to the other components in the wireless device1502. The power source may comprise one or more sources of power, forexample, a battery, a solar cell, a fuel cell, or any combinationthereof. The processing system 1508 and/or the processing system 1518may be connected to a GPS chipset 1517 and a GPS chipset 1527,respectively. The GPS chipset 1517 and the GPS chipset 1527 may beconfigured to provide geographic location information of the wirelessdevice 1502 and the base station 1504, respectively.

FIG. 16A illustrates an example structure for uplink transmission. Abaseband signal representing a physical uplink shared channel mayperform one or more functions. The one or more functions may comprise atleast one of: scrambling; modulation of scrambled bits to generatecomplex-valued symbols; mapping of the complex-valued modulation symbolsonto one or several transmission layers; transform precoding to generatecomplex-valued symbols; precoding of the complex-valued symbols; mappingof precoded complex-valued symbols to resource elements; generation ofcomplex-valued time-domain Single Carrier-Frequency Division MultipleAccess (SC-FDMA) or CP-OFDM signal for an antenna port; and/or the like.In an example, when transform precoding is enabled, a SC-FDMA signal foruplink transmission may be generated. In an example, when transformprecoding is not enabled, an CP-OFDM signal for uplink transmission maybe generated by FIG. 16A. These functions are illustrated as examplesand it is anticipated that other mechanisms may be implemented invarious embodiments.

FIG. 16B illustrates an example structure for modulation andup-conversion of a baseband signal to a carrier frequency. The basebandsignal may be a complex-valued SC-FDMA or CP-OFDM baseband signal for anantenna port and/or a complex-valued Physical Random Access Channel(PRACH) baseband signal. Filtering may be employed prior totransmission.

FIG. 16C illustrates an example structure for downlink transmissions. Abaseband signal representing a physical downlink channel may perform oneor more functions. The one or more functions may comprise: scrambling ofcoded bits in a codeword to be transmitted on a physical channel;modulation of scrambled bits to generate complex-valued modulationsymbols; mapping of the complex-valued modulation symbols onto one orseveral transmission layers; precoding of the complex-valued modulationsymbols on a layer for transmission on the antenna ports; mapping ofcomplex-valued modulation symbols for an antenna port to resourceelements; generation of complex-valued time-domain OFDM signal for anantenna port; and/or the like. These functions are illustrated asexamples and it is anticipated that other mechanisms may be implementedin various embodiments.

FIG. 16D illustrates another example structure for modulation andup-conversion of a baseband signal to a carrier frequency. The basebandsignal may be a complex-valued OFDM baseband signal for an antenna port.Filtering may be employed prior to transmission.

A wireless device may receive from a base station one or more messages(e.g., RRC messages) comprising configuration parameters of a pluralityof cells (e.g., primary cell, secondary cell). The wireless device maycommunicate with at least one base station (e.g., two or more basestations in dual-connectivity) via the plurality of cells. The one ormore messages (e.g., as a part of the configuration parameters) maycomprise parameters of physical, MAC, RLC, PCDP, SDAP, RRC layers forconfiguring the wireless device. For example, the configurationparameters may comprise parameters for configuring physical and MAClayer channels, bearers, etc. For example, the configuration parametersmay comprise parameters indicating values of timers for physical, MAC,RLC, PCDP, SDAP, RRC layers, and/or communication channels.

A timer may begin running once it is started and continue running untilit is stopped or until it expires. A timer may be started if it is notrunning or restarted if it is running. A timer may be associated with avalue (e.g., the timer may be started or restarted from a value or maybe started from zero and expire once it reaches the value). The durationof a timer may not be updated until the timer is stopped or expires(e.g., due to BWP switching). A timer may be used to measure a timeperiod/window for a process. When the specification refers to animplementation and procedure related to one or more timers, it will beunderstood that there are multiple ways to implement the one or moretimers. For example, it will be understood that one or more of themultiple ways to implement a timer may be used to measure a timeperiod/window for the procedure. For example, a random access responsewindow timer may be used for measuring a window of time for receiving arandom access response. In an example, instead of starting and expiry ofa random access response window timer, the time difference between twotime stamps may be used. When a timer is restarted, a process formeasurement of time window may be restarted. Other exampleimplementations may be provided to restart a measurement of a timewindow.

A UE is in an RRC connected state when an RRC connection has beenestablished. The UE is in an RRC idle state when no RRC connection isestablished. The UE may be in an RRC inactive state when RRC connectionis suspended. When the UE is in an RRC idle state, the UE may have asuspended RRC connection. Based on the suspended RRC connection in theRRC idle state, the UE is in an RRC idle state with a suspended RRCconnection.

RRC connection establishment may comprise the establishment of SRB1. Abase station may complete the

RRC connection establishment prior to completing the establishment ofthe S1 connection, (e.g., prior to receiving the UE context informationfrom core network entity (e.g., AMF)). access stratum (AS) security isnot activated during the initial phase of the RRC connection. During theinitial phase of the RRC connection, the base station may configure theUE to perform measurement reporting. The UE may send the correspondingmeasurement reports after successful AS security activation. The UE mayreceive or accept a handover message (e.g., a handover command) when ASsecurity has been activated.

After having initiated the initial (AS) security activation procedure, abase station may initiate establishment of

SRB2 and DRBs. For example, the base station may initiate establishmentof SRB2 and DRBs prior to receiving the confirmation of the initialsecurity activation from the UE. The base station may apply cipheringand integrity protection for the RRC (connection) reconfigurationmessages where the RRC reconfiguration message is used to establish SRB2and DRBs. The base station may release the RRC connection based on theinitial security activation and/ or the radio bearer establishment beingfailed. For example, security activation and DRB establishment may betriggered by a joint S1 procedure where the joint S1 procedure may notsupport partial success. For SRB2 and DRBs, (AS) security may beactivated from the start. For example, the base station may notestablish these bearers prior to activating security.

A base station may initiate suspension of the RRC connection. When theRRC connection is suspended, the

UE may store UE AS context and resume identity (or I-RNTI), andtransitions to RRC_IDLE state. The RRC message to suspend the RRCconnection is integrity protected and ciphered. The suspension may beperformed when at least 1 DRB is successfully established. Resumption ofthe suspended RRC connection is initiated by the UE (e.g., UE-NAS layer)when the UE has a stored UE AS context, RRC connection resume ispermitted by a base station and the UE needs to transit from an RRC idlestate to an RRC connected state. When the RRC connection is resumed, theUE (UE-RRC layer) may configure the UE according to the RRC connectionresume procedure based on the stored UE AS context and RRC configurationreceived from a base station. The RRC connection resume procedure mayre-activate (AS) security and re-establish SRB(s) and DRB(s). Therequest to resume the RRC connection (e.g., an RRC resume requestmessage) may include the resume identity. The request may be notciphered and protected with a message authentication code.

In response to a request to resume the RRC connection, a base station(or core network entities) may resume the suspended RRC connection,reject the request to resume and instruct the UE to either keep ordiscard the stored context, or setup a new RRC connection.

Based on CP EDT or CP transmission using PUR (e.g., CP small datatransmission), the data may be appended in an RRC early data request andan RRC early data complete messages and sent over SRBO. Based on UP EDTor UP transmission using PUR (e.g., UP small data transmission), (AS)security may be re-activated prior to transmission of RRC message usingnext hop chaining count provided in the RRC (connection) release messagewith suspend indication (e.g., suspend configuration parameters) duringthe preceding suspend procedure and the radio bearers may bere-established. The uplink data may be transmitted ciphered on DTCHmultiplexed with the RRC (connection) resume request message on CCCH. Inthe downlink, the data may be transmitted on DTCH multiplexed with theRRC (connection) release message on DCCH. In response to a request forEDT or transmission using PUR (e.g., small data transmission), a basestation may also choose to establish or resume the RRC connection.

A UE in an RRC connected state may transition to an RRC inactive statewhen a base station indicate RRC connection suspension in an RRC releasemessage. When transitioning to an RRC inactive state, the UE may storeUE Inactive AS context and RRC configuration received from the basestation. Resumption of an RRC connection from an RRC inactive state maybe initiated by the UE (e.g., UE-NAS layer) when the UE needs to transitfrom an RRC inactive state to an RRC connected state or by the UE (e.g.,UE-RRC layer) for RAN-based Notification Area update (RNAU) or receptionof RAN paging. When the RRC connection is resumed, a base station mayconfigure the UE according to the RRC connection resume procedure basedon the stored UE Inactive AS context and RRC configuration received froma base station. The RRC connection resume procedure may re-activate (AS)security and re-establish SRB(s) and DRB(s). In response to a request toresume the RRC connection from an RRC inactive state, the base stationmay resume the suspended RRC connection and the UE may transition to anRRC connected state. In response to a request to resume the RRCconnection from an RRC inactive state, the base station may reject therequest to resume using RRC message without security protection and sendUE to an RRC inactive state with wait time, or directly re-suspend theRRC connection and send UE to an RRC inactive state, or directly releasethe RRC connection and send UE to an RRC idle state, or instruct the UEto initiate NAS level recovery. Based on the NAS level recovery, the UEmay send NAS message (e.g., registration update message) to AMF.

Upon receiving the UE context from the core network entity (e.g., AMF),a base station may activate (AS) security (both ciphering and integrityprotection) using the initial security activation procedure. The RRCmessages to activate security (command and successful response) may beintegrity protected. Ciphering may be started only after completion ofthe initial security activation procedure. For example, the response tothe RRC message used to activate security may be not ciphered. Thesubsequent messages (e.g., used to establish SRB2 and DRBs) may be bothintegrity protected and ciphered.

A UE-RRC layer may initiate an RRC connection establishment procedure,an RRC connection resume procedure, or an RRC connectionre-establishment procedure. Based on initiating the RRC connectionestablishment procedure or the RRC connection resume procedure, the UEmay perform one or more procedures where the one or more procedurescomprise at least one of: performing a unified access control procedure(e.g., access barring check) for access attempt of the RRCestablishment/resume procedure on a serving cell; applying defaultconfigurations parameters and configurations/parameters provided bySIB1, (e.g., based on the access attempt being allowed, applying defaultconfigurations and configurations/parameters provided by SIB1);performing sending a random access preamble to the serving cell, forexample, based on the access attempt being allowed; sending an RRCrequest message to the serving cell (e.g., based on determining areception of a random access response being successful, sending an RRCrequest message to the serving cell0; starting a timer based on sendingthe RRC request message; receiving an RRC response message or an RRCreject message from the serving cell (e.g., in response to the RRCrequest message); or sending an RRC complete message (e.g., in responseto receiving the RRC response message, sending an RRC complete message).For the RRC connection re-establishment procedure, the UE may notperform the unified access procedure (e.g., access barring check) foraccess attempt of the RRC reestablishment procedure.

A base station (e.g., NG-RAN) may support overload and access controlfunctionality such as RACH back off,

RRC Connection Reject, RRC Connection Release and UE based accessbarring mechanisms. Unified access control framework applies to all UEstates (e.g., an RRC idle, inactive and connected state). The basestation may broadcast barring control information associated with accesscategories and access identities (in case of network sharing, thebarring control information may be set individually for each PLMN). TheUE may determine whether an access attempt is authorized based on thebarring information broadcast for the selected PLMN, the selected accesscategory and access identities for the access attempt. For NAS triggeredrequests, the UE-NAS layer may determine the access category and accessidentities. For AS triggered requests, the UE-RRC layer determines theaccess category while NAS determines the access identities. The basestation may handle access attempts with establishment causes“emergency”, “mps-priority access” and “mcs priority access” (i.e.,Emergency calls, MPS, MCS subscribers) with high priority and respondwith RRC Reject to these access attempts only in extreme network loadconditions that may threaten the base station stability.

Based on initiating the RRC connection establishment procedure or theRRC connection resume procedure, the UE in an RRC inactive or idle statemay perform or initiate access barring check (or a unified accesscontrol procedure) for access attempt of the RRC connectionestablishment procedure or the RRC connection resume procedure. Based onthe performing or initiating the access barring check, the UE maydetermine the access category and access identities for access attempt.The UE may determine the access attempt being barred based on at leastone of: timer T309 is running for the access category for the accessattempt; and timer T302 is running and the Access Category is neither‘2’ nor ‘0’. The UE may determine the access attempt being allowed basedon at least one of: the access Category is ‘0’; and system informationblock (system information block type 25) comprising unified accesscontrol (UAC) barring parameters is not broadcasted by a serving cell.The UE may determine the access attempt being barred based on at leastone of: an establishment cause (e.g., for the access attempt) beingother than emergency; access barring per RSRP parameter of the systeminformation block comprising (or being set to) threshold 0 and thewireless device being in enhanced coverage; access barring per RSRPparameter of the system information block comprising (or being set to)threshold 1 and measured RSRP being less than a first entry in RSRPthresholds PRACH info list; the access barring per RSRP parameter of thesystem information block comprising (or being set to) threshold 2 andmeasured RSRP being less than a second entry in the RSRP thresholdsPRACH info list; and the access barring per RSRP parameter of the systeminformation block comprising (or being set to) threshold 3 and measuredRSRP being less than a third entry in the RSRP thresholds PRACH infolist. The UE may determine the access attempt being allowed based onthat system information block not comprising the UAC barring parametersfor the access attempt. For example, the UE may determine the accessattempt being allowed based on that system information block notcomprising the UAC barring parameters for PLMN the UE selected and UACbarring parameters for common. The UE may determine the access attemptbeing allowed based on the UAC barring parameters for common notcomprising the access category of the access attempt. The UAC barringparameters may comprise at least one of: UAC barring parameters perPLMN; and UAC barring parameters for common. The UE may perform accessbarring check for the access category of the access attempt based on theUAC barring parameters in the system information block. The UE maydetermine the access attempt being allowed based on corresponding bit ofat least one of the access identities in the UAC barring parametersbeing zero. The UE may draw a first random number uniformly distributedin a range where the range is greater than equal to 0 and lower than 1.The UE may determine the access attempt being allowed based on the firstrandom number being lower than UAC barring factor in the UAC barringparameters. The UE may determine the access attempt being barred basedon the first random number being greater than the UAC barring factor inthe UAC barring parameters. In response to the determining the accessattempt being barred, the UE may draw a second random number uniformlydistributed in a range where the range is greater than equal to 0 andlower than 1. The UE may start barring timer T309 for the accesscategory based on the second random number. When the barring timer T309is running, the access attempt associated to the access category isbarred (e.g., not allowed to transmit). Based on the barring timer T309expiry, the UE may consider barring for the access category beingalleviated. Based on the barring for the access category beingalleviated, the UE may perform access barring check for the accesscategory if the UE have access attempt for the access category.

Based on initiating the RRC connection reestablishment procedure, the UEmay stop one or more barring timer T309 for all access categories if theone or more barring timer T309 is running. Based on stopping the one ormore barring timer T309, the UE may determine barring for the all accesscategories being alleviated. The UE may perform the RRC connectionreestablishement procedure based on the barring for the all accesscategories being alleviated. For example, the UE may send an RRCreestablishement request without barring based on the barring for theall access categories being alleviated.

For initiating RRC connection establishment/resume/reestablishmentprocedure, the UE-RRC layer may use parameters in a received SIB1. TheUE-RRC layer may use 1:1 parameter values and a time alignment timer inthe SIB1. The UE-RRC layer may use UAC barring information in the SIB1to perform the unified access control procedure. Based on the unifiedaccess control procedure, the UE-RRC layer may determine whether theaccess attempt of those RRC procedures is barred or allowed. Based onthe determining the access attempt is allowed, the UE-RRC layer maydetermine send an RRC request message to a base station where the RRCrequest message may be an RRC setup request message, an RRC resumerequest message, or an RRC re-establishment message. The UE-NAS layermay or may not provide S-TMSI as an UE identity. The UE-RRC layer mayset an UE identity in the RRC request message.

For the RRC setup request message, the UE in an RRC idle state mayinitiate an RRC connection establishment procedure. Based on initiatingthe RRC connection establishment procedure, the UE-RRC layer in an RRCidle state may set the UE identity to S-TMSI if the UE-NAS layerprovides the S-TMSI. Otherwise, the UE-RRC layer in an RRC idle statemay draw a 39-bit random value and set the UE identity to the randomvalue. For the RRC resume request messag, the UE-RRC layer in an RRCinactive or idle state may set the UE identity to resume identitystored. For the RRC reestablishment request message, the UE-RRC layer inan RRC connected state may set the UE identity to C-RNTI used in thesource PCell. The UE-NAS layer may provide an establishment cause (e.g.,UE-NAS layer). The UE-RRC layer may set the establishment cause for theRRC request message.

For the RRC resume request message, the UE in an RRC inactive mayinitiate an RRC connection resume procedure. the UE in an RRC idle statewith a suspended RRC connection may initiate the RRC connection resumeprocedure. The UE may in an RRC inactive or idle state may initiate theRRC connection procedure based on at least one of: resuming a (suspend)RRC connection; and performing/initiating UP small data transmission.Based on initiating the RRC connection resume procedure, the UE-RRClayer may restore stored configuration parameters and stored securitykeys from the stored UE inactive AS context. Based on the security keys,the UE-RRC layer in an RRC inactive or idle state may set a resume MAC-Ivalue to the 16 least significant bits of the MAC-I calculated based onvariable resume MAC input, security key of integrity protection for RRClayer in a UE inactive AS context, the previous configured integrityprotection algorithm, and other security parameters (e.g., count,bearer, and direction). The variable resume MAC input may comprise atleast one of: physical cell identity of a source cell; C-RNTI of thesource cell; and cell identity of a target cell (e.g., a selected cell)where the cell identity is a cell identity in system information block(e.g., SIB1) of the target cell (e.g., the selected cell). Based on thesecurity keys and next hop chaining count (NCC) value, the UE-RRC layerin an RRC inactive or idle state derive new security keys for integrityprotection and ciphering, and configure lower layers (e.g., UE-PDCPlayer) to apply them. The UE may have a stored NCC value and resumeidentity. The UE may receive an RRC release message with suspendindication (or suspend configuration parameters) where the RRC releasemessage comprises at least one of: the resume identity; and the NCCvalue. The UE-RRC layer in an RRC inactive or idle state mayre-establish PDCP entities for one or more bearers. The UE-RRC layer mayresume one or more bearer. For example, based on resuming the RRCconnection, the UE-RRC layer may resume SRB1. Based on performing the UPsmall data transmission, the UE-RRC layer may resume one or more SRB(s)and DRB(s). The UE-RRC layer in the RRC inactive or idle state may sendan RRC resume request message to the base station where the RRC resumerequest message may comprise at least one of: the resume identity; theresume MAC-I; and resume casue.

For the RRC reestablishment request message, the UE in an RRC connectedstate may initiate an RRC connection reestablishment procedure. Based oninitiating the RRC connection reestablishment procedure, the UE-RRClayer in an RRC connected state may contain the physical cell identityof the source PCell and a short MAC-I in the RRC reestablishmentmessage. The UE-RRC layer in an RRC connected state may set the shortMAC-I to the 16 east significant bits of the MAC-I calculated based onvariable short MAC input, security key of integrity protection for RRClayer and the integrity protection algorithm, which was used in a sourcePCell or the PCell in which the trigger for the reestablishmentoccurred, and other security parameters (e.g., count, bearer anddirection). The variable short MAC input may comprise at least one of:physical cell identity of the source cell; C-RNTI of a source cell; andcell identity of a target cell (e.g., a selected cell) where the cellidentity is a cell identity in system information block (e.g., SIB1) ofthe target cell (e.g., the selected cell). The UE-RRC layer in an RRCconnected state may re-establish PDCP entities and RLC entities for SRB1and apply default SRB1 configuration parameters for SRB1. The UE-RRClayer in an RRC connected state may configure lower layers (e.g., PDCPlayer) to suspend integrity protection and ciphering for SRB1 and resumeSRB1.

A UE-RRC layer may send an RRC request message to lower layers (e.g.,PDCP layer, RLC layer, MAC layer and/or PHY layer) for transmissionwhere where the RRC request message may be an RRC setup request message,an RRC resume request message, or an RRC re-establishment message.

A UE-RRC layer may receive an RRC setup message in response to an RRCresume request message or an RRC reestablishment request message. Basedon the RRC setup message, the UE-RRC layer may discard any sotred AScontext, suspend configuration parameters and current AS securitycontext. The UE-RRC layer may release radio resources for allestablished RBs except SRB0, including release of the RLC entities, ofthe associated PDCP entities and of SDAP. The UE-RRC layer may releasethe RRC configuration except for default L1 parameter values, defaultMAC cell group configuration and CCCH configuration. The UE-RRC layermay indicate to upper layers (e.g., NAS layer) fallback of the RRCconnection. The UE-RRC layer may stop timer T380 if running where thetimer T380 is periodic RAN-based Notification Area (RNA) update timer.

A UE-RRC layer may receive an RRC setup message in response to an RRCsetup request message, an RRC resume request message or an RRCreestablishment request message. The RRC setup message may comprise acell group configurations parameters and a radio bearer configurationparameters. The radio bearer configuration parameters may comprise atleast one of signaling bearer configuration parameters, data radiobearer configuration parameters and/or security configurationparameters. The security configuration parameters may comprise securityalgorithm configuration parameters and key to use indication indicatingwhether the radio bearer configuration parameters are using master keyor secondary key. The signaling radio bearer configuration parametersmay comprise one or more signaling radio bearer configurationparameters. Each signaling radio configuration parameters may compriseat least one of srb identity, PDCP configuration parameters,reestablishPDCP indication and/or discard PDCP indication. The dataradio bearer configuration parameters may comprise one or more dataradio bearer configuration parameters. Each data radio configurationparameters may comprise at least one of drb identity, PDCP configurationparameters, SDAP configuration parameters, reestablishPDCP indicationand/or recover PDCP indication. The radio bearer configuration in theRRC setup message may comprise signaling radio configuration parametersfor SIB1. Based on the RRC setup message, the UE-RRC layer may establishSRB1. Based on the RRC setup message, the UE-RRC layer may perform acell group configuration or radio bearer configuration. The UE-RRC layermay stop a barring timer and wait timer for the cell sending the RRCsetup message. Based on receiving the RRC setup message, the UE-RRClayer may perform one or more of the following: transitioning to RRCconnected state; stopping a cell re-selection procedure; considering thecurrent cell sending the RRC setup message to be the PCell; or/andsending an RRC setup complete message by setting the content of the RRCsetup complete message.

A UE-RRC layer may receive an RRC resume message in response to an RRCresume request message. Based on the RRC resume message, the UE-RRClayer may discard a UE inactive AS context and release a suspendconfiguration parameters except ran notification area information. Basedon the configuration parameters in the RRC resume message, the UE-RRClayer may perform a cell group configuration, a radio bearerconfiguration, security key update procedure, measurement configurationprocedure. Based on receiving the RRC resume message, the UE-RRC layermay perform one or more of the following: indicating upper layers (e.g.,NAS layer) that the suspended RRC connection has been resumed; resumingSRB2, all DRBs and measurements; entering RRC connected state; stoppinga cell re-selection procedure; considering the current cell sending theRRC resume message to be the PCell; or/and sending an RRC resumecomplete message by setting the content of the RRC resume completemessage.

The cell group configuration parameters may comprise at least one of RLCbearer configuration parameters, MAC cell group configurationparameters, physical cell group configuration parameters, SpCellconfiguration parameters for the first cell group or SCell configurationparameters for other cells of the second base station. The SpCellconfiguration parameter may comprise at least one of radio link failuretimer and constraints, radio link monitoring in sync out of syncthreshold, and/or serving cell configuration parameters of the firstcell. The serving cell configuration parameters may comprise at leastone of: downlink BWP configuration parameters; uplink configurationparameters; uplink configuration parameters for supplement uplinkcarrier (SUL); PDCCH parameters applicable across for all BWPs of aserving cell; PDSCH parameters applicable across for all BWPs of aserving cell; CSI measurement configuration parameters; SCelldeactivation timer; cross carrier scheduling configuration parametersfor a serving cell; timing advance group (TAG) identity (ID) of aserving cell; path loss reference linking indicating whether the UEshall apply as pathloss reference either the downlink of SpCell or SCellfor this uplink; serving cell measurement configuration parameters;channel access configuration parameters for access procedures ofoperation with shared spectrum channel access;

The CSI measurement configuration parameters may be to configure CSI-RS(reference signals) belonging to the serving cell, channel stateinformation report to configure CSI-RS (reference signals) belonging tothe serving cell and channel state information reports on PUSCHtriggered by DCI received on the serving cell.

In an example, the downlink BWP configuration parameters may be used toconfigure dedicated (UE specific) parameters of one or more downlinkBWPs. The one or more downlink BWPs may comprise at least one of aninitial downlink BWP, a default downlink BWP and a first active downlinkBWP. The downlink BWP configuration parameters may comprise at least oneof: configuration parameters for the one or more downlink BWPs; one ormore downlink BWP IDs for the one or more downlink BWPs; and BWPinactivity timer. The configuration parameters for a downlink BWP maycomprise at least one of: PDCCH configuration parameters for thedownlink BWP; PDSCH configuration parameters for the downlink BWP;semi-persistent scheduling (SPS) configuration parameters for thedownlink BWP; beam failure recovery SCell configuration parameters ofcandidate RS; and/or radio link monitoring configuration parameters fordetecting cell- and beam radio link failure occasions for the downlinkBWP. The one or more downlink BWP IDs may comprise at least one of aninitial downlink BWP ID, a default downlink BWP identity (ID) and afirst active downlink BWP ID.

In an example, the uplink configuration parameters may be uplinkconfiguration parameters for normal uplink carrier (not supplementaryuplink carrier). The uplink configuration parameters (or the uplinkconfiguration parameters for SUL) may be used to configure dedicated (UEspecific) parameters of one or more uplink BWPs. The one or more uplinkBWPs may comprise at least one of an initial uplink BWP and a firstactive uplink BWP. The uplink BWP configuration parameters may compriseat least one of: configuration parameters for the one or more uplinkBWPs; one or more uplink BWP IDs for the one or more uplink BWPs; PUSCHparameters common across the UE's BWPs of a serving cell; SRS carrierswitching information; and power control configuration parameters. Theconfiguration parameters for a uplink BWP may comprise at least one of:one or more PUCCH configuration parameters for the uplink BWP; PUSCHconfiguration parameters for the uplink BWP; one or more configuredgrant configuration parameters for the uplink BWP; SRS configurationparameters for the uplink BWP; beam failure recovery configurationparameters for the uplink BWP; and/or cyclic prefix (CP) extensionparameters for the uplink BWP.

The one or more uplink BWP IDs may comprise at least one of an initialuplink BWP ID (e.g., the initial uplink

BWP ID=0) and/or an first active uplink BWP ID. The SRS carrierswitching information may be is used to configure for SRS carrierswitching when PUSCH is not configured and independent SRS power controlfrom that of PUSCH. The power control configuration parameters maycomprise at least one of power control configuration parameters forPUSCH, power configuration control parameters for PUCCH and powercontrol parameters for SRS.

A UE-RRC layer in an RRC inactive or idle state may receive an RRCreject message in response to an RRC setup request message or an RRCresume request message. The RRC reject message may contain wait timer.Based on the wait timer, the UE-RRC layer may start timer T302, with thetimer value set to the wait timer. Based on the RRC reject message, theUE-RRC layer may inform upper layers (e.g., UE-NAS layer) about thefailure to setup an RRC connection or resume an RRC connection. TheUE-RRC layer may reset MAC and release the default MAC cell groupconfiguration. Based on the RRC Reject received in response to a requestfrom upper layers, the UE-RRC layer may inform the upper layer (e.g.,NAS layer) that access barring is applicable for all access categoriesexcept categories ‘0’ and ‘2’.

A UE-RRC layer in an RRC inactive or idle state may receive an RRCreject message in response to an RRC resume request message. Based onthe RRC reject message, The UE-RRC layer may discard current securitykeys. The UE-RRC layer may re-suspend the RRC connection. The UE-RRClayer may set pending ma update value to true if resume is triggered dueto an RNA update.

A UE-RRC layer in an RRC inactive or idle state may perform a cell(re)selection procedure while performing an RRC procedure to establishan RRC connection. Based on cell selection or cell reselection, theUE-RRC layer may change a cell on the UE camped and stop the RRCprocedure. The UE-RRC layer may inform upper layers (e.g., NAS layer)about the failure of the RRC procedure.

A UE in RRC idle or RRC inactive state may perform one of two proceduressuch as initial cell selection and cell selection by leveraging storedinformation. The UE may perform the initial cell selection when the UEdoesn't have stored cell information for the selected PLMN. Otherwise,the UE may perform the cell selection by leveraging stored information.For initial cell selection, a UE may scan all RF channels in the NRbands according to its capabilities to find a suitable cell. Based onresults of the scan, the UE may search for the strongest cell on eachfrequency. The UE may select a cell which is a suitable cell. For thecell selection by leveraging stored information, the UE may requiresstored information of frequencies and optionally also information oncell parameters from previously received measurement control informationelements or from previously detected cells. Based on the storedinformation, the UE may search a suitable cell and select the suitablecell if the UE found the suitable cell. If the UE does not found thesuitable cell, the UE may perform the initial cell selection.

A base station may configure cell selection criteria for cell selection.a UE may seek to identify a suitable cell for the cell selection. Thesuitable cell is one for which satisfies following conditions: (1) themeasured cell attributes satisfy the cell selection criteria, (2) thecell PLMN is the selected PLMN, registered or an equivalent PLMN, (3)the cell is not barred or reserved, and (4) the cell is not part oftracking area which is in the list of “forbidden tracking areas forroaming”. An RRC layer in a UE may inform a NAS layer in the UE of cellselection and reselection result based on changes in received systeminformation relevant for NAS. For example, the cell selection andreselection result may be a cell identity, tracking area code and a PLMNidentity.

A UE in an RRC connected state may detect a failure of a connection witha base station. The UE in the RRC connected state may activate ASsecurity with the base station before the detecting the failure. Thefailure comprises at least one of: a radio link failure (RLF); areconfiguration with sync failure; a mobility failure from new radio(NR); an integrity check failure indication from lower layers (e.g.,PDCP layer) concerning signaling radio bearer 1 (SRB1) or signalingradio bearer 2 (SRB2); or an RRC connection reconfiguration failure.

The radio link failure may be a radio link failure of a primary cell ofthe base station. The base station may send a reconfiguration with syncin an RRC message to the UE in RRC connected state. The reconfigurationwith sync may comprise a reconfiguration timer (e.g., T304). Based onreceiving the reconfiguration sync, the UE may start the reconfigurationtimer and perform the reconfiguration with sync (e.g., handover). Basedon expiry of the reconfiguration timer, the UE determine thereconfiguration sync failure. A base station may send mobility from NRcommand message to the UE in RRC connected state. Based on receiving themobility from NR command message, the UE may perform to handover from NRto a cell using other RAT (e.g., E-UTRA). The UE may determine themobility failure from NR based on at least one of conditions being met:if the UE does not succeed in establishing the connection to the targetradio access technology; or if the UE is unable to comply with any partof the configuration included in the mobility from NR command message;or if there is a protocol error in the inter RAT information included inthe mobility from NR message.

Based on detecting the failure, the UE in the RRC connected state mayinitiate an RRC connection reestablishment procedure. Based oninitiating the RRC connection reestablishment procedure, the UE maystart a timer T311, suspend all radio bearers except for SRBO, reset MAC(layer). Based on initiating the RRC connection reestablishmentprocedure, the UE in the RRC connected state may release MCG SCells,release special cell (SpCell) configuration parameters and multi-radiodual connectivity (MR-DC) related configuration parameters. For example,based on initiating the RRC connection reestablishment procedure, the UEmay release master cell group configuration parameters.

Cell group configuration parameters may be used to configure a mastercell group (MCG) or secondary cell group (SCG). If the cell groupconfiguration parameters are used to configure the MCG, the cell groupconfiguration parameters are master cell group configuration parameters.If the cell group configuration parameters are used to configure theSCG, the cell group configuration parameters are secondary cell groupconfiguration parameters. A cell group comprises of one MAC entity, aset of logical channels with associated RLC entities and of a primarycell (SpCell) and one or more secondary cells (SCells). The cell groupconfiguration parameters (e.g., master cell group configurationparameters or secondary cell group configuration parameters) maycomprise at least one of RLC bearer configuration parameters for thecell group, MAC cell group configuration parameters for the cell group,physical cell group configuration parameters for the cell group, SpCellconfiguration parameters for the cell group or SCell configurationparameters for the cell group. The MAC cell group configurationparameters may comprise MAC parameters for a cell group wherein the MACparameters may comprise at least DRX parameters. The physical cell groupconfiguration parameters may comprise cell group specific L1 (layer 1)parameters.

The special cell (SpCell) may comprise a primary cell (PCell) of an MCGor a primary SCG cell (PSCell) of a

SCG. The SpCell configuration parameters may comprise serving cellspecific MAC and PHY parameters for a SpCell. The MR-DC configurationparameters may comprise at least one of SRB3 configuration parameters,measurement configuration parameter for SCG, SCG configurationparameters.

Based on initiating the RRC connection reestablishment procedure, the UEin the RRC connected state may perform a cell selection procedure. Basedon the cell selection procedure, the UE may select a cell based on asignal quality of the cell exceeding a threshold. The UE in the RRCconnected state may select a cell based on a signal quality of the cellexceeding a threshold. The UE may determine, based on a cell selectionprocedure, the selected cell exceeding the threshold. The signal qualitycomprises at least one of: a reference signal received power; a receivedsignal strength indicator; a reference signal received quality; or asignal to interference plus noise ratio.

Based on selecting a suitable cell, the UE in the RRC connected statemay stop the timer 311 and start a timer T301. Based on selecting thesuitable cell, the UE in the RRC connected state may stop a barringtimer T390 for all access categories. Based on stopping the barringtimer T390, the UE in the RRC connected state may consider a barring forall access category to be alleviated for the cell. Based on selectingthe cell, the UE in the RRC connected state may apply the default L1parameter values except for the parameters provided in SIB1, apply thedefault MAC cell group configuration, apply the CCCH configuration,apply a timer alignment timer in SIB1 and initiate transmission of theRRC reestablishment request message.

The UE in the RRC connected state may stop the timer T301 based onreception of an RRC response message in response of the RRCreestablishment request message. The RRC response message may compriseat least one of RRC reestablishment message or RRC setup message or RRCreestablishment reject message. The UE in the RRC connected state maystop the timer T301 when the selected cell becomes unsuitable.

Based on the cell selection procedure triggered by initiating the RRCconnection reestablishment procedure, the UE in the RRC connected statemay select an inter-RAT cell. Based on selecting an inter-RAT cell, theUE (UE-AS layer) in the RRC connected state may transition to RRC IDLEstate and may provide a release cause ‘RRC connection failure’ to upperlayers (UE-NAS layer) of the UE.

Based on initiating the transmission of the RRC reestablishment requestmessage, the UE in the RRC connected state may send the RRCreestablishment request message. The RRC reestablishment request messagemay comprise at least one of C-RNTI used in the source PCell, a physicalcell identity (PCI) of the source PCell, short MAC-I or areestablishment cause. The reestablishment cause may comprise at leastone of reconfiguration failure, handover failure or other failure.

Based on initiating the transmission of the RRC reestablishment requestmessage, the UE (RRC layer) in the RRC connected state may re-establishPDCP for SRB1, re-establish RLC for SRB1, apply default SRBconfigurations for SRB1, configure lower layers (PDCP layer) to suspendintegrity protection and ciphering for SRB1, resume SRB1 and submit theRRC reestablishment request message to lower layers (PDCP layer) fortransmission. Based on submitting the RRC reestablishment requestmessage to lower layers, the UE in the RRC connected state may send theRRC reestablishment request message to a target base station via thecell selected based on the cell selection procedure wherein the targetbase station may or may not be the source base station.

Based on expiry of the timer T311 or T301, the UE (UE-AS layer) maytransition to an RRC idle state and may provide a release cause ‘RRCconnection failure’ to upper layers (UE-NAS layer) of the UE.

Based on receiving the release cause ‘RRC connection failure’, the UE(UE-NAS layer) in the RRC idle state may perform a NAS signalingconnection recovery procedure when the UE does not have signalingpending and user data pending. Based on performing the NAS signalingconnection recovery procedure, the UE in the RRC idle state may initiatethe registration procedure by sending a Registration request message tothe AMF.

Based on receiving the release cause ‘RRC connection failure’, the UE(UE-NAS layer) in the RRC idle state may perform a service requestprocedure by sending a service request message to the AMF when the UEhas signaling pending or user data pending.

Based on receiving the RRC reestablishment request message, the targetbase station may check whether the UE context of the UE is locallyavailable. Based on the UE context being not locally available, thetarget base station may perform a retrieve UE context procedure bysending a retrieve UE context request message to the source base station(the last serving base station) of the UE.

For RRC connection reestablishment procedure, the retrieve UE contextrequest message may comprise at least one of: a UE context ID; integrityprotection parameters; or a new cell identifier. The UE context ID maycomprise at least one of: C-RNTI contained the RRC reestablishmentrequest message; and a PCI of the source PCell (the last serving PCell).The integrity protection parameters for the RRC reestablishmentprocedure may be the short MAC-I. The new cell identifier may be anidentifier of the target cell wherein the target cell is a cell wherethe RRC connection has been requested to be re-established. The new cellidentifier is a cell identity in system information block (e.g., SIB1)of the target cell (e.g., the selected cell).

For the RRC connection reestablishment procedure, based on receiving theretrieve UE context request message, the source base station may checkthe retrieve UE context request message. If the source base station isable to identify the UE context by means of the UE context ID, and tosuccessfully verify the UE by means of the integrity protectioncontained in the retrieve UE context request message, and decides toprovide the UE context to the target base station, the source basestation may respond to the target base station with a retrieve UEcontext response message. If the source base station is not able toidentify the UE context by means of the UE context ID, or if theintegrity protection contained in the retrieve UE context requestmessage is not valid, the source base station may respond to the targetbase station with a retrieve UE context failure message.

For the RRC connection reestablishment procedure, the retrieve UEcontext response message may comprise at least one of Xn applicationprotocol (XnAP) ID of the target base station, XnAP ID of the sourcebase station, globally unique AMF identifier (GUAMI) or UE contextinformation (e.g., UE context information retrieve UE context response).The UE context information may comprise at least one of a NG-C UEassociated signaling reference, UE security capabilities, AS securityinformation, UE aggregate maximum bit rate, PDU session to be setuplist, RRC context, mobility restriction list or index to RAT/frequencyselection priority. The NG-C UE associated signaling reference may be aNG application protocol ID allocated at the AMF of the UE on the NG-Cconnection with the source base station. The AS security information maycomprise a security key of a base station (K_(gNB)) and next hopchaining count (NCC) value. The PDU session to be setup list maycomprise PDU session resource related information used at UE context inthe source base station. The PDU session resource related informationmay comprise a PDU session ID, a PDU session resource aggregate maximumbitrate, a security indication, a PDU session type or QoS flows to besetup list. The security indication may comprise a user plane integrityprotection indication and confidentiality protection indication whichindicates the requirements on user plane (UP) integrity protection andciphering for the corresponding PDU session, respectively. The securityindication may also comprise at least one of an indication whether UPintegrity protection is applied for the PDU session, an indicationwhether UP ciphering is applied for the PDU session and the maximumintegrity protected data rate values (uplink and downlink) per UE forintegrity protected DRBs. The PDU session type may indicate at least oneof internet protocol version 4 (IPv4), IPv6, IPv4v6, ethernet orunstructured. The QoS flow to be setup list may comprise at least one ofQoS flow identifier, QoS flow level QoS parameters (the QoS Parametersto be applied to a QoS flow) or bearer identity.

For the RRC connection reestablishment procedure, the retrieve UEcontext failure message may comprise at least XnAP ID of the target basestation and a cause value.

For the RRC connection reestablishment procedure, based on receiving theretrieve UE context response message, the target base station may sendan RRC reestablishment message to the UE. The RRC reestablishmentmessage may comprise at least a network hop chaining count (NCC) value.

Based on receiving the RRC reestablishment message, the UE may derive anew security key of a base station (K_(gNB)) based on at least one ofcurrent K_(gNB) or next hop (NH) parameters associated to the NCC value.Based on the new security key of the base station and a previouslyconfigured integrity protection algorithm, the UE may derive a securitykey for integrity protection of an RRC signaling (K_(RRCint)) and asecurity key for integrity protection of user plane (UP) data(K_(UPint)). Based on the new security key of the base station and apreviously configured ciphering algorithm, the UE may derive a securitykey for ciphering of an RRC signaling (K_(RRCenc)) and a security keyfor ciphering of user plane (UP) data (K_(UPenc)). Based on theK_(RRCint), and the previously configured integrity protectionalgorithm, the UE may verify the integrity protection of the RRCreestablishment message. Based on the verifying being failed, the UE(UE-AS layer) may go to RRC IDLE state and may provide a release cause‘RRC connection failure’ to upper layers (UE-NAS layer) of the UE. Basedon the verifying being successful, the UE may configure to resumeintegrity protection for SRB1 based on the previously configuredintegrity protection algorithm and the K_(RRCint) and configure toresume ciphering for SRB1 based on the previously configured cipheringalgorithm and K_(RRCenc). The UE may send an RRC reestablishmentcomplete message to the target base station.

Based on receiving the retrieve UE context failure message, the targetbase station may send an RRC release message to the UE. For example,based on the retrieve UE context failure message comprising the RRCrelease message, the target base station may send the RRC releasemessage to the UE. Based on receiving the retrieve UE context failuremessage, the target base station may send an RRC setup message or an RRCreject message. Based on receiving the retrieve UE context failuremessage, the target base station may not send any response message tothe UE.

FIG. 17 illustrates an example of an RRC connection reestablishmentprocedure. The UE in an RRC connected state may send and receive datato/from a first base station (for example, a source base station) via acell 1 wherein the cell 1 is a primary cell (PCell) of the first basestation. The UE may detect a failure of a connection with the first basestation. Based on the failure, the UE may initiate the RRCreestablishment procedure.

Based on initiating the RRC connection reestablishment procedure, the UEmay start a timer T311, suspend all radio bearers except for SRBO,and/or reset a MAC (layer). Based on initiating the RRC connectionreestablishment procedure, the UE may release MCG SCells, release thespecial cell (SpCell) configuration parameters and the multi-radio dualconnectivity (MR-DC) related configuration parameters. Based oninitiating the RRC connection reestablishment procedure, the UE mayperform a cell selection procedure. Based on the cell selectionprocedure, the UE may select a cell 2 of a second base station (forexample, a target base station) wherein the cell 2 is a suitable cell.Based on selecting a suitable cell, the UE may stop the timer T311 andstart a timer T301. Based on selecting the suitable cell, the UE maystop one or more barring timer T309(s) for all access categories if theone or more barring timer T309(s) is running. Based on stopping the oneor more barring timer T309(s), the UE may consider barring for allaccess category to be alleviated for the cell. Based on selecting thecell, the UE may apply the default L1 parameter values except for theparameters provided in SIB1, apply the default MAC cell groupconfiguration, apply the CCCH configuration, apply a timer alignmenttimer in SIB1 and initiate transmission of the RRC reestablishmentrequest message.

The RRC reestablishment message may comprise at least one of C-RNTI usedin the source PCell (e.g., the cell 1), a physical cell identity (PCI)of the source PCell, short MAC-I or a reestablishment cause. Based oninitiating the transmission of the RRC reestablishment request message,the UE (RRC layer) may re-establish PDCP for SRB1, re-establish RLC forSRB1, apply default SRB configurations for SRB1, configure lower layers(PDCP layer) to suspend integrity protection and ciphering for SRB1,resume SRB1 and submit the RRC reestablishment request message to lowerlayers (PDCP layer) for transmission. Based on initiating thetransmission of the RRC reestablishment request message, the UE may sendthe RRC reestablishment request message to the second base station viathe cell 2.

Based on receiving the RRC reestablishment request message, the secondbase station may check whether the UE context of the UE is locallyavailable. Based on the UE context being not locally available, thesecond base station may perform the retrieve UE context procedure bysending a retrieve UE context request message to the source base stationof the UE. the retrieve UE context request message may comprise at leastone of: a UE context ID; integrity protection parameters; or a new cellidentifier. The UE context ID may comprise at least one of: C-RNTIcontained the RRC reestablishment request message; and a PCI of thesource PCell (the last serving PCell). The integrity protectionparameters for the RRC reestablishment procedure may be the short MAC-I.The new cell identifier may be an identifier of the target cell whereinthe target cell is a cell where the RRC connection has been requested tobe re-established. The new cell identifier is a cell identity in systeminformation block (e.g., SIB1) of the target cell (e.g., the selectedcell).

Based on receiving the retrieve UE context request message, the sourcebase station may check the retrieve UE context request message. If thesource base station is able to identify the UE context by means of theC-RNTI, and to successfully verify the UE by means of the short MAC-I,and decides to provide the UE context to the second base station, thesource base station may respond to the second base station with aretrieve UE context response message. The retrieve UE context responsemessage may comprise at least of GUAMI or the UE context information.Based on receiving the retrieve UE context response message, the secondbase station may send an RRC reestablishment message to the UE. The RRCreestablishment message may comprise a network hop chaining count (NCC)value.

Based on receiving the RRC reestablishment message, the UE may derive anew security key of a base station (K_(gNB)) based on at least one ofcurrent K_(gNB) or next hop (NH) parameters associated to the NCC value.Based on the new security key of a base station (K_(gNB)) and thepreviously configured security algorithms, the UE may derive securitykeys for integrity protection and ciphering of RRC signaling (e.g.,K_(RRCint) and K_(RRCenc) respectively) and user plane (UP) data (e.g.,K_(UPint) and K_(UPenc) respectively). Based on the security key forintegrity protection of the RRC signaling (K_(RRCint)), the UE mayverify the integrity protection of the RRC reestablishment message.Based on the verifying being successful, the UE may configure to resumeintegrity protection for one or more bearers (e.g., signalling radiobearer or an RRC message) based on the previously configured integrityprotection algorithm and the K_(RRCint) and configure to resumeciphering for one or more bearers based on the previously configuredciphering algorithm and the K_(RRCenc).

The second base station may send a first RRC reconfiguration message.The RRC first reconfiguration message may comprise the SpCellconfiguration parameters. Based on receiving the SpCell configurationparameters, the UE may initiate transmission and reception of datato/from the second base station. The UE may send an RRC reestablishmentcomplete message to the second base station. The RRC reestablishmentcomplete message may comprise measurement report. Based on receiving themeasurement report, the second base station may determine to configureSCells and/or secondary cell groups (e.g., SCG or PSCells). Based on thedetermining, the second base station may send a second RRCreconfiguration message comprising SCells configuration parametersand/or MR-DC related configuration parameters. Based receiving thesecond RRC reconfiguration message, the UE may transmit and receive datavia the SCells and/or SCGs.

The RRC reconfiguration message may comprise at least one of cell groupconfiguration parameters of MCG and/or SCG, radio bearer configurationparameters or AS security key parameters.

A UE may remain in CM-CONNECTED and move within an area configured bythe base station without notifying the base station when the UE is inRRC inactive state where the area is an RNA. In RRC inactive state, alast serving base station may keep the UE context and the UE-associatedNG connection with the serving AMF and UPF. Based on received downlinkdata from the UPF or downlink UE-associated signaling from the AMF whilethe UE is in RRC inactive state, the last serving base station may pagein the cells corresponding to the RNA and may send RAN Paging via an Xninterface to neighbor base station(s) if the RNA includes cells ofneighbor base station(s).

An AMF may provide to the base station a core network assistanceinformation to assist the base station's decision whether a UE can besent to RRC inactive state. The core network assistance information mayinclude the registration area configured for the UE, the periodicregistration update timer, a UE identity index value, the UE specificDRX, an indication if the UE is configured with mobile initiatedconnection only (MICO) mode by the AMF, or the expected UE behavior. Thebase station may use the UE specific DRX and the UE identity index valueto determine a paging occasion for RAN paging. The base station may useperiodic registration update timer to configure periodic RNA updatetimer (e.g., a timer T380). The base station may use an expected UEbehavior to assist the UE RRC state transition decision.

A base station may initiate an RRC connection release procedure totransit an RRC state of a UE from RRC connected state to RRC idle state,from an RRC connected state to RRC inactive state, from RRC inactivestate back to RRC inactive state when the UE tries to resume, or fromRRC inactive state to RRC idle state when the UE tries to resume. TheRRC connection procedure may also be used to release an RRC connectionof the UE and redirect a UE to another frequency. The base station maysend the RRC release message comprising suspend configuration parameterswhen transitioning RRC state of the UE to RRC inactive state. Thesuspend configuration parameters may comprise at least one of a resumeidentity, RNA configuration, RAN paging cycle, or network hop chainingcount (NCC) value wherein the RNA configuration may comprise RNAnotification area information, or periodic RNA update timer value (e.g.,T380 value). The base station may use the resume identity (e.g.,inactive-RNTI (I-RNTI)) to identify the UE context when the UE is in RRCinactive state.

If the base station has a fresh and unused pair of {NCC, next hop (NH)},the base station may include the NCC in the suspend configurationparameters. Otherwise, the base station may include the same NCCassociated with the current K_(gNB) in the suspend configurationparameters. The NCC is used for AS security. The base station may deletethe current AS keys (e.g., K_(RRCenc), K_(UPenc)) and K_(UPint) aftersending the RRC release message comprising the suspend configurationparameters to the UE but may keep the current AS key K_(RRCint). If thesent NCC value is fresh and belongs to an unused pair of {NCC, NH}, thebase station may save the pair of {NCC, NH} in the current UE ASsecurity context and may delete the current AS key K_(gNB). If the sentNCC value is equal to the NCC value associated with the current K_(gNB),the base station may keep the current AS key K_(gNB) and NCC. The basestation may store the sent resume identity together with the current UEcontext including the remainder of the AS security context.

Upon receiving the RRC release message comprising the suspendconfiguration parameters from the base station, the UE may verify thatthe integrity of the received RRC release message comprising the suspendconfiguration parameters is correct by checking PDCP MAC-I. If thisverification is successful, then the UE may take the received NCC valueand save it as stored NCC with the current UE context. The UE may deletethe current AS keys KRRcenc, K_(RRCenc), K_(UPenc), and K_(upint), butkeep the current AS key K_(RRCint) key. If the stored NCC value isdifferent from the NCC value associated with the current K_(gNB), the UEmay delete the current AS key K_(gNB). If the stored NCC is equal to theNCC value associated with the current K_(gNB), the UE shall keep thecurrent AS key KgNB. The UE may store the received resume identitytogether with the current UE context including the remainder of the ASsecurity context, for the next state transition.

Based on receiving the RRC release message comprising the suspendconfiguration parameters, the UE may reset MAC, release the default MACcell group configuration, re-establish RLC entities for one or morebearers. Based on receiving the RRC release message comprising suspendconfiguration parameters, the UE may store in the UE inactive AS contextcurrent configuration parameters and current security keys. For example,the UE may store some of the current configuration parameters. Thestored current configuration parameters may comprise a robust headercompression (ROHC) state, quality of service (QoS) flow to DRB mappingrules, the C-RNTI used in the source PCell, the global cell identity andthe physical cell identity of the source PCell, and all other parametersconfigured except for the ones within reconfiguration with sync andserving cell configuration common parameters in SIB. The stored securitykeys may comprise at least one of K_(gNB) and K_(RRCint). The servingcell configuration common parameters in SIB may be used to configurecell specific parameters of a UE's serving cell in SIB1. Based onreceiving the RRC release message comprising the suspend configurationparameters, the UE may suspend all SRB(s) and DRB(s) except for SRBO.Based on receiving the RRC release message comprising suspendconfiguration parameters, the UE may start a timer T380, enter RRCinactive state, perform cell selection procedure.

The UE in RRC inactive state may initiate an RRC connection resumeprocedure. For example, based on having data or signaling to transmit,or receiving RAN paging message, the UE in RRC inactive state mayinitiate the RRC connection resume procedure. Based on initiating theRRC connection resume procedure, the UE may select access category basedon triggering condition of the RRC connection resume procedure andperform unified access control procedure based on the access category.Based on the unified access control procedure, the UE may consideraccess attempt for the RRC connection resume procedure as allowed. Basedon considering the access attempt as allowed, the UE may apply thedefault L1 parameter values as specified in corresponding physical layerspecifications, except for the parameters for which values are providedin SIB1, apply the default SRB1 configuration, apply the CCCHconfiguration, apply the time alignment timer common included in SIB1,apply the default MAC cell group configuration, start a timer T319 andinitiate transmission of an RRC resume request message.

Based on initiating the transmission of the RRC resume request message,the UE may set the contents of the RRC resume request message. The RRCresume request message may comprise at least one of resume identity,resume MAC-I or resume cause. The resume cause may comprise at least oneof emergency, high priority access, mt access, mo signalling, mo data,mo voice call, mo sms, ran update, mps priority access, mcs priorityaccess.

Based on initiating the transmission of the RRC resume request message,the UE may restore the stored configuration parameters and the storedsecurity keys from the (stored) UE inactive AS context except for themaster cell group configuration parameters, MR-DC related configurationparameters (e.g., secondary cell group configuration parameters) andPDCP configuration parameters. The configuration parameter may compriseat least one of the C-RNTI used in the source PCell, the global cellidentity and the physical cell identity of the source PCell, and allother parameters configured except for the ones within reconfigurationwith sync and serving cell configuration common parameters in SIB. Basedon current (restored) K_(gNB) or next hop (NH) parameters associated tothe stored NCC value, the UE may derive a new key of a base station(K_(gNB)). Based on the new key of the base station, the UE may derivesecurity keys for integrity protection and ciphering of RRC signalling(e.g., K_(RRCenc) and K_(RRCint) respectively) and security keys forintegrity protection and ciphering of user plane data (e.g., KUPInt andthe KUPenc respectively). Based on configured algorithm and theK_(RRCint) and K_(UPint), the UE may configure lower layers (e.g., PDCPlayer) to apply integrity protection for all radio bearers except SRBO.Based on configured algorithm and the KRRcenc and the KuPenc, the UE mayconfigure lower layers (e.g., PDCP layer) to apply ciphering for allradio bearers except SRBO.

Based on initiating the transmission of the RRC resume request message,the UE may re-establish PDCP entities for one or more bearers, resumethe one or more bearers and submit the RRC resume request message tolower layers wherein the lower layers may comprise at least one of PDCPlayer, RLC layer, MAC layer or physical (PHY) layer.

A target base station may receive the RRC resume request message. Basedon receiving the RRC resume request message, the target base station maycheck whether the UE context of the UE is locally available. Based onthe UE context being not locally available, the target base station mayperform the retrieve UE context procedure by sending the retrieve UEcontext request message to the source base station (the last servingbase station) of the UE. The retrieve UE context request message maycomprise at least one of a UE context ID, integrity protectionparameters, a new cell identifier or the resume cause wherein the resumecause is in the RRC resume request message.

For the RRC connection resume procedure, based on receiving the retrieveUE context request message, the source base station may check theretrieve UE context request message. If the source base station is ableto identify the UE context by means of the UE context ID, and tosuccessfully verify the UE by means of the integrity protectioncontained in the retrieve UE context request message, and decides toprovide the UE context to the target base station, the source basestation may respond to the target base station with the retrieve UEcontext response message. If the source base station is not able toidentify the UE context by means of the UE context ID, or if theintegrity protection contained in the retrieve UE context requestmessage is not valid, or, if the source base station decides not toprovide the UE context to the target base station, the source basestation may respond to the target base station with a retrieve UEcontext failure message.

For the RRC connection resume procedure, the retrieve UE context failuremessage may comprise at least XnAP ID of the target base station, an RRCrelease message or a cause value.

For the RRC connection resume procedure, based on receiving the retrieveUE context response message, the target base station may send an RRCresume message to the UE. The RRC resume message may comprise at leastone of radio bearer configuration parameters, cell group configurationparameters for MCG and/or SCG, measurement configuration parameters orsk counter wherein the sk counter is used to derive a security key ofsecondary base station based on K_(gNB).

Based on receiving the retrieve UE context failure message, the targetbase station may send an RRC release message to the UE. For example,based on the retrieve UE context failure message comprising the RRCrelease message, the target base station may send the RRC releasemessage to the UE. Based on receiving the retrieve UE context failuremessage, the target base station may send an RRC setup message or an RRCreject message. Based on receiving the retrieve UE context failuremessage, the target base station may not send any response message tothe UE.

Based on receiving the RRC resume message, the UE may stop the timerT319 and T380. Based on receiving the RRC resume message, the UE mayrestore mater cell group configuration parameters, secondary cell groupconfiguration parameters and PDCP configuration parameters in the UEinactive AS context. Based on restoring the master cell groupconfiguration parameter and/or the secondary cell group configurationparameters, the UE may configure SCells of MCG and/or SCG by configuringlower layers to consider the restored MCG and/or SCG SCells to be indeactivated state, discard the UE inactive AS context and release thesuspend configuration parameters.

Based on receiving the cell group configuration parameters in the RRCresume message, the UE may perform cell group configuration of MCGand/or SCG. Based on receiving the radio bearer configuration parametersin the RRC resume message, the UE may perform radio bearerconfiguration. Based on the sk counter in the RRC resume message, the UEmay perform to update the security key of secondary base station.

FIG. 18 illustrates an example of an RRC connection resume procedure. AUE in RRC connected state may transmit and receive data to/from a firstbase station (a source base station) via a cell 1. The first basestation may determine to transit a UE in RRC connected state to RRCinactive state. Based on the determining, the base station may send anRRC release message comprising the suspend configuration parameters.

Based on receiving the RRC release message comprising suspendconfiguration parameters, the UE may store in the UE inactive AS Contextthe current security keys (e.g., K_(gNB) and K_(RRCint) keys) andcurrent configuration parameters. For example, the UE may store some ofthe current configuration parameters. The stored (current) configurationparameters may be at least one of: robust header compression (ROHC)state; QoS flow to DRB mapping rules; C-RNTI used in source PCell;global cell identity and physical cell identity of the source PCell; andall other parameters configured except for ones within reconfigurationwith sync and serving cell configuration common parameters in SIB. Therobust header compression (ROHC) state may comprise ROHC states for allPDCP entity (or all bearers) where each PDCP entity per bearer (or eachbearer) may have one ROHC state. The QoS flow to DRB mapping rules maybe QoS flow to DRB mapping rules for all data radio bearer (DRB) whereeach DRB may have one QoS follow to DRB mapping rule.

Based on receiving the RRC release message comprising suspendconfiguration parameters, the UE may suspend all SRB(s) and DRB(s)except for SRBO. Based on receiving the RRC release message comprisingsuspend configuration parameters, the UE may start a timer T380, enterRRC inactive state, perform cell selection procedure. Based on the cellselection procedure, the UE may select a cell 2 of a second base station(a target base station). The UE in RRC inactive state may initiate anRRC connection resume procedure. The UE may perform the unified accesscontrol procedure. Based on the unified access control procedure, the UEmay consider access attempt for the RRC connection resume procedure asallowed. The UE may apply the default 1:1 parameter values as specifiedin corresponding physical layer specifications, except for theparameters for which values are provided in SIB1, apply the default SRB1configuration, apply the CCCH configuration, apply the time alignmenttimer common included in SIB1, apply the default MAC cell groupconfiguration, start a timer T319 and initiate transmission of an RRCresume request message.

Based on initiating the transmission of the RRC resume request message,the UE may restore the stored configuration parameters and the storedsecurity keys from the (stored) UE inactive AS context. For example, theUE may restore the stored configuration parameters and the storedsecurity keys (e.g., K_(gNB) and K_(RRCint)) from the stored UE InactiveAS context except for the master cell group configuration parameters,MR-DC related configuration parameters (e.g., secondary cell groupconfiguration parameters) and PDCP configuration parameters. Based oncurrent (restored) K_(gNB) or next hop (NH) parameters associated to thestored NCC value, the UE may derive a new key of a base station(K_(gNB)). Based on the new key of the base station, the UE may derivesecurity keys for integrity protection and ciphering of RRC signalling(e.g., K_(RRCenc) and K_(RRCint) respectively) and security keys forintegrity protection and ciphering of user plane data (e.g., K_(UPint)and the K_(UPenc) respectively). Based on configured algorithm and theK_(RRCint) and K_(UPint), the UE (RRC layer) may configure lower layers(e.g., PDCP layer) to apply integrity protection for all radio bearersexcept SRBO. Based on configured algorithm and the KRRCenc and the KuPenc, the UE may configure lower layers (e.g., PDCP layer) to applyciphering for all radio bearers except SRBO. For communication betweenthe UE and the base station, the integrity protection and/or theciphering may be required. Based on the integrity protection and/or theciphering, the UE may be able to transmit and receive data to/from thesecond base station. The UE may use the restored configurationparameters to transmit and receive the data to/from the second basestation.

Based on initiating the transmission of the RRC resume request message,the UE may re-establish PDCP entities for one or more bearers, resumeone or more bearers and submit the RRC resume request message to lowerlayers. Based on receiving the RRC resume request message, the secondbase station may check whether the UE context of the UE is locallyavailable. Based on the UE context being not locally available, thesecond base station may perform the retrieve UE context procedure bysending the retrieve UE context request message to the first basestation (the last serving base station) of the UE. The retrieve UEcontext request message may comprise at least one of: resume identity;resume MAC-I; or the resume cause.

Based on receiving the retrieve UE context request message, the firstbase station may check the retrieve UE context request message. If thefirst base station is able to identify the UE context by means of the UEcontext ID, and to successfully verify the UE by means of the resumeMAC-I and decides to provide the UE context to the second base station,the first base station may respond to the second base station with theretrieve UE context response message. Based on receiving the retrieve UEcontext response message, the second base station may send an RRC resumemessage to the UE. Based on receiving the RRC resume message, the UE mayrestore mater cell group configuration parameters, secondary cell groupconfiguration parameters and PDCP configuration parameters in the UEinactive AS context. Based on restoring the master cell groupconfiguration parameter and/or the secondary cell group configurationparameters, the UE may configure SCells of MCG and/or SCG by configuringlower layers to consider the restored MCG and/or SCG SCells to be indeactivated state, discard the UE inactive AS context and release thesuspend configuration parameters. The UE may transmit and receive datavia the SCells and/or SCGs.

The RRC resume message may comprise at least one of cell groupconfiguration parameters of MCG and/or SCG, radio bearer configurationparameters or AS security key parameters (e.g., sk counter).

A base station may send an RRC release message to a UE to release an RRCconnection of the UE. Based on the RRC release message, the UE mayrelease established radio bearers as well as all radio resources.

A base station may send an RRC release message to a UE to suspend theRRC connection. Based on the RRC release message, the UE may suspend allradio bearers except for signaling radio bearer 0 (SRB0). The RRCrelease message may comprise suspend configuration parameters. Thesuspend configuration parameters may comprise next hop chaining count(NCC) and resume identity (e.g., ID or identifier).

The base station may send an RRC release message to transit a UE in anRRC connected state to an RRC idle state; or to transit a UE in an RRCconnected state to an RRC inactive state; or to transit a UE in an RRCinactive state back to an RRC inactive state when the UE tries toresume; or to transit a UE in an RRC inactive state to an RRC idle statewhen the UE tries to resume.

The base station may send an RRC release message to redirect a UE toanother frequency.

A UE may receive an RRC release message from the base station of servingcell (or PCell). Based on the RRC release message, the UE may performsUE actions for the RRC release message from the base station. The UE maydelay the UE actions for the RRC release message a period of time (e.g.,60 ms) from the moment the RRC release message was received or when thereceipt of the RRC release message was successfully acknowledged. The UEmay send HARQ acknowledgments to the base station for acknowledgments ofthe RRC release message. Based on a RLC protocol data unit (PDU)comprising the RRC release message and the RLC PDU comprising poll bit,the UE may send a RLC message (e.g., a status report) to the basestation for acknowledgments of the RRC release message.

The UE actions for the RRC release message from the base station maycomprise at least one of: suspending

RRC connection; releasing RRC connection; cell (re)selection procedure;and/or idle/inactive measurements.

The RRC release message from the base station may comprise the suspendconfiguration parameters. Based on the suspend configuration parameters,the UE may perform the suspending RRC connection. The suspending RRCconnection may comprise at least one of: medium access control (MAC)reset (or resetting MAC); releasing default MAC cell groupconfiguration; re-establishing RLC entities for one or more radiobearers; storing current configuration parameters and current securitykeys; suspending one or more bearers where the bearers comprisessignaling radio bearer and data radio bearer; and/or transitioning anRRC idle state or an RRC inactive state.

For example, the suspend configuration parameters may further compriseRNA configuration parameters.

Based on the RNA configuration parameters, the UE may transition to anRRC inactive state. For example, based on the suspend configurationparameters not comprising the RNA configuration parameters, the UE maytransition to an RRC idle state. For example, the RRC release messagecomprising the suspend configuration parameters may comprise aindication transitioning to an RRC inactive state. Based on theindication, the UE may transition to an RRC inactive state. For example,based on the RRC release message not comprising the indication, the UEmay transition to an RRC idle state.

Based on the MAC reset, the UE may perform to at least one of: stop alltimers running in the UE-MAC layer;

consider all time alignment timers as expired; set new data indicators(NDIs) for all uplink HARQ processes to the value 0; stop, ongoing RACHprocedure; discard explicitly signaled contention-free Random AccessResources, if any; flush Msg 3 buffer; cancel, triggered schedulingrequest procedure; cancel, triggered buffer status reporting procedure;cancel, triggered power headroom reporting procedure; flush the softbuffers for all DL HARQ processes; for each DL HARQ process, considerthe next received transmission for a TB as the very first transmission;and/or release, temporary C-RNTI.

Based on the considering the time alignment timers as expired, the UEmay perform at least one of: flush all HARQ buffers for all servingcells; notify RRC to release PUCCH for all Serving cells, if configured;notify RRC to release SRS for all Serving Cells, if configured; clearany configured downlink assignments and configured uplink grants; clearany PUSCH resource for semi-persistent CSI reporting; and/or considerall running time alignment timers as expired.

The default MAC cell group configuration parameters may comprise bufferstatus report (BSR) configuration parameters (e.g., BSR timers) for acell group of the base station and power headroom reporting (PHR)configuration parameters (e.g., PHR timers or PHR transmission powerfactor change parameter) for the cell group of the base station.

The re-establishing RLC entities may comprise at least one of:discarding all RLC SDUs, RLC SDU segments, and RLC PDUs, if any;stopping and resetting all timers of the RLC entities; and resetting allstate variables of the RLC entities to their initial values.

The RRC release message from the base station may not comprise thesuspend configuration parameters.

Based on the RRC message not comprising the suspend configurationparameters, the UE may perform the releasing RRC connection. Thereleasing RRC connection may comprise at least one of: MAC reset (orresetting MAC); discarding the stored configuration parameters andstored security keys (or discarding the stored UE inactive AS context);releasing the suspend configuration parameters; releasing all radioresources, including release of RLC entity, MAC configuration andassociated PDCP entity and SDAP for all established radio bearers;and/or transitioning to an RRC idle state.

The RRC release message may be RRC early data complete message.

A UE may send or receive a small amount of data without transitioningfrom an RRC idle state or an RRC inactive state to an RRC connectedstate based on performing small data transmission. The performing smalldata transmission may comprise, while staying in the RRC idle state orthe RRC inactive state (e.g., without transitioning to an RRC connectedstate), at least one of: initiating small data transmission; sendingsmall data; and/or receiving a response message.

For example, based on the small data transmission, the UE in an RRC idlestate or an RRC inactive state may perform initiating small datatransmission. In response to the initiating small data transmission, theUE in an RRC idle state or an RRC inactive state may perform sendingsmall data. In response to the sending small data, the UE may receive aresponse message. For example, the response message may comprise adownlink data (or a downlink signaling). For example, based on the smalldata transmission, the UE in an RRC idle state or an RRC inactive statemay perform sending small data. In response to the sending small data,the UE in an RRC idle state or an RRC inactive state may receive aresponse message. The sending small data may comprise at least one ofsending at least one of an RRC request message, uplink data (or uplinksignaling) or buffer status report (BSR). For example, the sending smalldata may comprise sending the RRC request message. For example, thesending small data may comprise sending the RRC request message anduplink data. For example, the sending small data may comprise sendingthe RRC request message, a first uplink data and the BSR requestinguplink resource for a second uplink data. The RRC request message maycomprise at least one of: an RRC resume request message; or an RRC earlydata request message. The response message may comprise at least one of:an RRC response message in response to the RRC request message; downlinkdata; or acknowledgment for uplink data (e.g., the first uplink data);or uplink resource for uplink data (e.g., the second uplink data). TheRRC response message for the RRC request message may comprise at leastone of: an RRC release message; an RRC early data complete message; anRRC setup message; an RRC resume message; or an RRC reject message.

Based on receiving the RRC release message, the UE in an RRC idle stateor an RRC inactive sate may transition to the RRC idle state or the RRCinactive state or stay in the RRC idle state or the RRC inactive state.Based receiving the RRC early data complete message, the UE in an RRCidle state or an RRC inactive sate may transition to the RRC idle state(or stay in the RRC idle state). Based on receiving the RRC releasemessage or the RRC early data complete message, the UE may considersending small data being successful. Based on receiving the RRC setupmessage or the RRC resume message, the UE in an RRC idle state or an RRCinactive state may transition to an RRC connected state. Based onreceiving the RRC setup message or the RRC resume message, the UE mayconsider sending small data being successful. Based on receiving the RRCreject message, the UE in an RRC idle state or an RRC inactive state maytransition to an RRC idle state. Based on receiving the RRC rejectmessage, the UE may consider sending small data being not successful.

FIG. 19 illustrates an example of small data transmission. Based onreceiving a first RRC release message, a UE may transition to an RRCinactive or an RRC idle state. The UE in an RRC inactive or idle statemay initiate small data transmission. The UE in an RRC inactive or idlestate may initiate the small data transmission based on having smalldata to transmit or based on receiving paging message. For example, thepaging message may indicate the small data transmission. Based on theinitiating the small data transmission, the UE in an RRC idle state oran RRC inactive state may transmit a message for the small datatransmission to a base station. The message may be Msg 3 or Msg A. Themessage may comprise at least one of: uplink data and an RRC requestmessage. The wireless device may transmit the message on UL-SCHcontaining at least one of: C-RNTI MAC CE; CCCH SDU; and DTCH. Forexample, the wireless device may multiplex the CCCH SDU and the DTCH inthe message. The wireless device may transmit the message to the basestation. For example, the CCCH SDU may be associated with the UEcontention resolution identity, as part of a random access procedure.For example, the UE in an RRC idle state or an RRC inactive state maysend the CCCH SDU using a configured grant (e.g., configured uplinkgrant, preconfigured uplink resource (PUR), etc.). The CCCH SDU maycomprise at least one of the RRC request message and the uplink data(e.g., the first uplink data). The DTCH may comprise the uplink data(e.g., the first uplink data).

In an example of the FIG. 19 , based on the transmitting the message forthe small data transmission, the UE in an RRC idle state or an RRCinactive state may receive downlink data in response to the transmittingthe message without transitioning to an RRC connected state. Forexample, based on the initiating the small data transmission, the UE inan RRC idle state or an RRC inactive state may transmit the messagecomprising at least one of; the RRC request message; and uplink data.the UE in the RRC idle state or the RRC inactive state may receive atleast one of the RRC response message and/or downlink data in responseto the RRC request message. The RRC response message may comprise an RRCrelease message. The RRC release message may comprise a second RRCrelease message wherein the RRC release message may comprise thedownlink data. Based on the second RRC release message, the UE maytransition to an RRC inactive or idle state.

The small data transmission may comprise user plane (UP) small datatransmission and control plane (CP) small data transmission. Based onthe UP small data transmission, the UE in an RRC idle state or an RRCinactive may transmit uplink data via user plane (e.g., via DTCH). Basedon the CP small data transmission, the UE in an RRC idle state or an RRCinactive may send uplink data via control plane (e.g., CCCH). Based onthe UP small data transmission, the base station of the UE may receivedownlink data via user plane from UPF of the UE. Based on the CP smalldata transmission, the base station of the UE may receive downlink datavia control plane from AMF of the UE. In response to the CCCH SDU and/orthe DTCH SDU, the base station may send a response message to the UE inan RRC idle state or an RRC inactive.

The small data transmission may comprise at least one of initiatingsmall data transmission, transmitting a message for the small datatransmission and receiving a response message for the message. Forexample, the UP small data transmission may comprise at least one of:initiating UP small data transmission; transmitting a message for the UPsmall data transmission (or UP small data via user plane); and receivinga response message. The CP small data transmission may comprise at leastone of: initiating the CP small data transmission; transmitting amessage for CP small data transmission (or CP small data via controlplane); and receiving a response message.

The initiating small data transmission may comprise at least one of:initiating UP small data transmission; and CP small data transmission.The transmitting a message for small data transmission may comprise atleast one of: transmitting a message for UP small data transmission; andtransmitting a message for CP small data transmission. The responsemessage may be a response message in response to at least one of: themessage; an RRC request message; and/or (first) uplink data.

For the UP small data transmission, the DTCH SDU may comprise the uplinkdata (for the small data transmission). For example, for the UP smalldata transmission, the UE may send the DTCH SDU multiplexed with CCCHSDU. For example, for the UP small data transmission, the CCCH SDU maycomprise an RRC request message. For example, for the UP small datatransmission, the RRC request message may be an RRC resume requestmessage.

For the CP small data transmission, the UE may send CCCH SDU comprisingthe uplink data. For example, for the CP small data transmission, theRRC request message may comprise the uplink data. For example, for theCP small data transmission, the RRC request message may be an RRC earlydata request message.

The small data transmission may comprise at least one of early datatransmission (EDT) and preconfigured uplink resource (PUR) transmission(or (small data) transmission using the PUR). The EDT may compriserandom access procedure while the PUR may not comprise the random accessprocedure. For the small data transmission, the UE in an RRC idle stateor an RRC inactive state may need uplink resource(grant) to send themessage for the small data transmission (e.g., the uplink data). Theuplink resource may comprise dynamic uplink resource or pre-configureduplink resource from a base station. For the EDT, the UE may receive theuplink resource (e.g., the dynamic uplink resource) in response to arandom access preamble. For example, the random access preamble may beconfigured for EDT. The random access preamble may be a dedicated randomaccess preamble for the EDT. The random access preamble may request theuplink resource for the EDT.

The UP small data transmission may comprise UP EDT and UP PUR (or UP(small data) transmission using the PUR). The CP small data transmissionmay comprise CP EDT and CP PUR (or CP (small data) transmission usingthe PUR). Small data transmission using PUR may comprise at least oneof: UP small data transmission using PUR; and CP small data transmissionusing PUR.

A UE in an RRC inactive state or an RRC idle state may determine toinitiate small data transmission based on condition for small datatransmission being met. The condition may comprise at least one of: EDTcondition; and PUR condition. The EDT condition may comprise at leastone of: UP EDT condition and CP EDT condition.

A UE in an RRC inactive state or an RRC idle state may determine toinitiate small data transmission for UP EDT based on UP EDT conditionbeing met. The UP EDT condition may comprise at least one of: common EDTconditions; and UP EDT specific condition. The UP EDT specific conditionmay comprise at least one of that: the UE supports UP EDT; systeminformation of a serving cell indicates UP EDT support; and the UE has astored NCC value provided in the RRC release message comprising suspendconfiguration parameters during the preceding suspend procedure.

The common EDT conditions may comprise at least one of: for mobileoriginating calls, the size of the resulting MAC PDU including the totaluplink data is expected to be smaller than or equal to largest transportblock size (TBS) for Msg 3 applicable to a UE performing EDT; and/orestablishment or resumption request is for mobile originating calls andthe establishment cause is mo data or mo exception data or delaytolerant access.

A UE in an RRC inactive state or an RRC idle state may determine toinitiate small data transmission for CP

EDT based on CP EDT condition being met. The CP EDT condition maycomprise the common EDT conditions and CP EDT specific condition. The CPEDT specific condition may comprise at least one of: the UE supports CPEDT; and system information of a serving cell indicates CP EDT support.

FIG. 20 illustrates an example of EDT. Based on receiving a first RRCrelease message from a base station, a UE may transition to an RRCinactive or an RRC idle state. The UE may have a first uplink data inuplink buffer. The UE in the RRC idle state or the RRC inactive statemay determine to initiate small data transmission based on at least oneof: the UP EDT condition; or the CP EDT condition being met. In responseto the initiating the small data transmission, the UE may perform EDTRACH procedure. Based on the EDT RACH procedure, the UE may select arandom access preamble configured for EDT and send the random accesspreamble to the base station. In response to the random access preambleconfigured for EDT, the UE may receive uplink resource/grant for EDT.Based on the uplink resource/grant for EDT, the UE may send a messagefor the small data transmission. For example, the message may compriseat least one of: an RRC request message; and/or the first uplink datausing the uplink resource for EDT.

In an example of the FIG. 20 , the UE in the RRC idle state or the RRCinactive may receive a response message in response to at least one of:the message; the RRC request message; and/or the first uplink data. Theresponse message may comprise an RRC release message. The RRC releasemessage may comprise downlink data. Based on receiving the responsemessage, the UE in the RRC idle state or the RRC inactive may considerthe small data transmission being successful. Based on the considering,the UE in the RRC idle state or the RRC inactive may empty at least oneof uplink buffer for the first uplink data. For example, in response toMsg 3 (or Msg A) comprising at least one the RRC request message and/orthe first uplink data, the UE in the RRC idle state or the RRC inactivemay receive Msg 4 (or Msg B). The Msg 4 may comprise an RRC releasemessage.

In an example of the FIG. 20 , based on receiving the Msg 4, the UE inthe RRC idle state or the RRC inactive may consider the small datatransmission being successful. Based on the considering, the UE in theRRC idle state or the RRC inactive may empty at least one of uplinkbuffer for the first uplink data and/or uplink buffer for the RRCrequest message. For example, based on the considering, the UE in theRRC idle state or the RRC inactive may flush at least one of HARQ bufferfor the first uplink data and/or HARQ buffer for the RRC requestmessage. Based on the RRC release message not comprising a suspendconfiguration parameters, the UE in the RRC idle state or the RRCinactive may perform the releasing RRC connection. For example, based onthe releasing RRC connection, the UE in the RRC idle state or the RRCinactive may transition to an RRC idle state. Based on the RRC releasemessage comprising a suspend configuration parameters, the UE in the RRCidle state or the RRC inactive may perform the suspending RRC connectionusing the suspend configuration parameters. For example, based on thesuspending RRC connection using the suspend configuration parameters,the UE may transition an RRC state of the UE from RRC inactive stateback to RRC inactive state or from RRC idle state back to an RRC idlestate.

A UE in an RRC connected state may communicate with a first base stationbased on first configuration parameters and first security keys. Thefirst base station may send an RRC release message to the UE. Based onreceiving the RRC release message comprising the first suspendconfiguration parameters, the UE may perform the suspending RRCconnection based on the first suspend configuration parameters. The UEmay transition to an RRC idle state or an RRC inactive state. Based onthe RRC release message, the UE may perform a cell (re)selectionprocedure. Based on the cell (re)selection procedure, the UE in the RRCidle state or the RRC inactive state may select a cell 2 of a secondbase station (a target base station). The UE in an RRC idle state or anRRC inactive state may determine to initiate UP small data transmissionbased on the UP EDT conditions being met. Based on the initiating UPsmall data transmission, the UE in the RRC idle state or the RRCinactive state may perform the initiating UP small data transmissionusing the first suspend configuration parameters. In response to theinitiating UP small data transmission, the UE in an RRC idle state or anRRC inactive may perform EDT RACH procedure. Based on the EDT RACHprocedure, the UE may select a random access preamble configured for EDTand transmit the random access preamble to the second base station viathe cell 2. In response to the random access preamble configured forEDT, the UE in the RRC idle state or the RRC inactive state may receive(dynamic) uplink resource for EDT. Based on the uplink resource for EDT,the UE in an RRC idle state or an RRC inactive may perform the sendingUP small data using the first suspend configuration parameters. Forexample, the UE in an RRC idle state or an RRC inactive may send uplinkdata using the uplink resource for EDT.

For the PUR transmission, a UE may in an RRC connected state send PURconfiguration request message to a base station where the PURconfiguration request message may comprise at least one of: requestednumber of PUR occasions where the number may be one or infinite;requested periodicity of PUR; requested transport block size (TBS) forPUR; and/or requested time offset for a first PUR occasion.

Based on the PUR configuration request message, the base station maysend PUR configuration parameters comprising the preconfigured uplinkresource to the UE. For example, in response to the PUR configurationrequest message, the base station may send PUR configuration parameterscomprising the preconfigured uplink resource to the UE. For example, thebase station may send an RRC release message comprising the PURconfiguration parameters.

The PUR configuration parameters may comprise at least one of: anindication to setup or release PUR configuration parameters; number ofPUR occasions; PUR resource identifier (PUR-RNTI); value of the timeoffset for a first PUR occasion (PUR start time); periodicity of PURresource (PUR periodicity); duration of PUR response window (PURresponse window time); threshold(s) of change in serving cell RSRP in dBfor TA validation (PUR change threshold(s)) where the thresholdscomprise RSRP increase threshold and RSRP decrease threshold; value oftime alignment timer for PUR; and/or physical configuration parametersfor PUR. The physical configuration parameters for PUR may comprises atleast one of: PUSCH configuration parameters for FUR; PDCCHconfiguration parameters for FUR; PUCCH configuration parameters forFUR; downlink carrier configuration parameters used for FUR; and/oruplink carrier frequency of the uplink carrier used for PUR.

A UE may determine to initiate small data transmission for PUR (or(small data) transmission using PUR) based on PUR conditions being met.The PUR conditions may comprise at least one of: the UE has a valid PURconfiguration parameters; the UE has a valid timing alignment (TA)value; and/or establishment or resumption request is for mobileoriginating calls and the establishment cause is mo data or mo exceptiondata or delay tolerant access.

The PUR conditions may further comprise at least one of: the UE supportsFUR; system information of a serving cell indicates PUR support; and/orthe UE has a stored NCC value provided in the RRC release messagecomprising suspend configuration parameters during the preceding suspendprocedure.

The UE may determine the timing alignment value for small datatransmission for PUR to being valid based on

TA validation conditions for PUR being met. The TA validation conditionsfor PUR may comprise at least one of: the time alignment timer for PURis running; or serving cell RSRP has not increased by more than the RSRPincrease threshold and has not decreased by more than the RSRP increasethreshold.

In response to receiving the PUR configuration parameters, the UE maystore or replace PUR configuration parameters provided by the PURconfiguration parameters based on the indication requesting to setup PURconfiguration parameters. In response to receiving the PUR configurationparameters, the UE may start a time alignment timer for PUR with thevalue of time alignment timer for PUR and configure the PURconfiguration parameters. For example, based on the indicationrequesting to setup PUR configuration parameters, the UE may start atime alignment timer for PUR with the value of time alignment timer forPUR and configure the PUR configuration parameters. In response toreceiving the PUR configuration parameters, the UE may discard PURconfiguration parameters based on the indication requesting to releasePUR configuration parameters. In response to the configuring the PURconfiguration parameters, the UE may generate preconfigured uplinkresource/grant for PUR based on the PUR configuration parameters. Forexample, based on the PUR configuration parameters, the UE may determinewhen generating the preconfigured uplink resource/grant. For example,based on the PUR start time and the PUR periodicity, the UE maydetermine when generating the preconfigured uplink resource/grant. Forexample, based on the PUSCH configuration parameters, the UE maydetermine (transport blocks for) the preconfigured uplinkresource/grant. For example, based on the PUSCH configurationparameters, the UE may determine (transport blocks for) thepreconfigured uplink resource/grant.

FIG. 21 illustrates an example of PUR. Based on receiving a first RRCrelease message, the UE may transition to an RRC idle state or an RRCinactive state. The UE may receive PUR configuration parameters viaprevious RRC release message. The previous RRC release message may bethe first RRC release message. In response to receiving the PURconfiguration parameters, the UE in an RRC idle state or an RRC inactivestate may start a time alignment timer for PUR with the value of timealignment timer for PUR and configure the PUR configuration parameters.In response to the configuring the PUR configuration parameters, the UEin the RRC idle state or the RRC inactive state may generatepreconfigured uplink resource/grant for PUR based on the PURconfiguration parameters. Based on the first RRC release message, the UEmay perform a cell (re)selection procedure. Based on the cell(re)selection procedure, the UE in an RRC idle state or an RRC inactivestate may select a cell 2 of a second base station (a target basestation). The UE in the RRC idle state or the RRC inactive state mayhave a first uplink data in uplink buffer or receive a paging message.The UE in the RRC idle state or the RRC inactive state may determine toinitiate the small data transmission for PUR based on the PUR conditionbeing met. For example, in response to the having the first uplink dataor receiving paging message, the UE in the RRC idle state or the RRCinactive state may determine to initiate the small data transmissionbased on the PUR condition being met. Based on the initiating, the UEmay transmit the message for the small data transmission. The UE maytransmit the message using the PUR (or the uplink resource/grant forPUR), the UE may perform the sending small data. The message maycomprise at least one of: an RRC request message; and/or the firstuplink data. For example, the message may be Msg 3 (or Msg A) comprisingat least one of CCCH SDU and/or DTCH SDU where the CCCH SDU comprises anRRC request message and the DTCH SDU comprises the first uplink data.

In an example of the FIG. 21 , in response to the transmitting themessage using the PUR (or the uplink resource/grant for PUR), the UE(UE-MAC entity) may start PUR response window timer with the PURresponse window time. Based on the starting, the UE may monitor PDCCHidentified by PUR RNTI until the PUR response window timer is expired.The UE (UE-MAC entity) may receive a downlink message (e.g., DCI)identified by the PUR RNTI on the PDCCH. Based on receiving the downlinkmessage indicating an uplink grant for retransmission, the UE mayrestart the PUR response window timer at last subframe of a PUSCHtransmission indicating the uplink grant, puls time gap (e.g., 4subframes). Based on the restarting, the UE in the RRC idle state or theRRC inactive state may monitor PDCCH identified by PUR RNTI until thePUR response window timer is expired. Based on receiving the downlinkmessage indicating L1 (layer 1) ack for PUR, the UE in the RRC idlestate or the RRC inactive state may stop the PUR response window timerand consider the small data transmission using PUR successful. Based onreceiving the downlink message indicating fallback for PUR, the UE inthe RRC idle state or the RRC inactive state may stop the PUR responsewindow timer and consider the small data transmission using PUR beingfailed. Based on receiving the downlink message indicating PDCCHtransmission (downlink grant or downlink assignment) addressed to thePUR RNTI and/or MAC PDU comprising the uplink data being successfullydecoded, the UE in the RRC idle state or the RRC inactive state may stopthe PUR response window timer and consider the small data transmissionusing PUR successful. Based on the PDCCH transmission, the UE in the RRCidle state or the RRC inactive state may receive at least one of an RRCresponse message and downlink data wherein the RRC response message atleast one of an RRC release message or an RRC early data completemessage. Based on not receiving any downlink message until the PURresponse window timer being expired, the UE in the RRC idle state or theRRC inactive state may consider the small data transmission using PURbeing failed. Based on considering the small data transmission using PURbeing failed, the UE may perform random access procedure. For example,the random access procedure may comprise EDT RACH procedure.

In an example, a UE in an RRC connected state may communicate with afirst base station based on first configuration parameters and firstsecurity keys. The first base station may send an RRC release message tothe UE. Based on receiving the RRC release message comprising the firstsuspend configuration parameters, the UE may perform the suspending RRCconnection based on the first suspend configuration parameters. The UEmay transition to an RRC idle state or an RRC inactive state. The UE mayreceive PUR configuration parameters via previous RRC release message.The previous RRC release message may be the RRC release message. Inresponse to receiving the PUR configuration parameters, the UE in theRRC idle state or the RRC inactive state may start a time alignmenttimer for PUR with the value of time alignment timer for PUR andconfigure the PUR configuration parameters. In response to theconfiguring the PUR configuration parameters, the UE the RRC idle stateor the RRC inactive state may generate preconfigured uplinkresource/grant for PUR based on the PUR configuration parameters. Basedon the RRC release message, the UE the RRC idle state or the RRCinactive state may perform a cell (re)selection procedure. Based on thecell (re)selection procedure, the UE in the RRC idle state or the RRCinactive state may select a cell 2 of a second base station (a targetbase station). The UE in the RRC idle state or the RRC inactive statemay determine to initiate small data transmission using PUR based on thePUR conditions being met. For example, the UE in the RRC idle state orthe RRC inactive state may initiate the small data transmission usingthe first suspend configuration parameters. Based on the (preconfigured)uplink resource for PUR, the UE in the RRC idle state or the RRCinactive state may transmit the message for the small data transmissionusing the first suspend configuration parameters.

In an example, a UE in an RRC idle state or an RRC inactive may at leastone of: transmit one or more uplink data to a base station; and receiveone or more uplink data from a base station. For example, a UE in an RRCidle state or an RRC inactive may determine to initiate a small datatransmission. Based on the initiating, the UE in the RRC idle state orthe RRC inactive may transmit a message for the small data transmissionto a base station. The message may comprise at least one of: an RRCrequest message for the small data transmission; uplink data; andassistance parameters indicating the small data transmission. Theassistance parameters may indicate traffic information of the small datatransmission. For example, the assistance parameters may indicatesubsequent data of the uplink data being expected. The assistanceparameters may indicate subsequent uplink data in uplink buffer of thewireless device. The base station may send uplink grant for thesubsequent data. The UE may transmit or receive the subsequent datawithout transitioning to an RRC connected state (e.g., while in the RRCidle state or the RRC inactive). For example, based on the message, thebase station may determine to allow transmission/reception withouttransitioning to an RRC connected state (e.g., while in the RRC idlestate or the RRC inactive). Based on the determining, the base stationmay send the uplink grant for the subsequent data.

In an example, a base station distributed unit may determine to requesta base station central unit to release (UE) context of the wirelessdevice (or UE-associated logical F1 connection). Based on thedetermining, the base station distributed unit may transmit the contextrelease request message to the base station central unit.

In an example, a base station central unit may determine to release (UE)context of the wireless device (or UE-associated logical F1 connection).Based on the determining, the base station distributed unit may transmitthe context release request message to the base station central unit.The base station central unit may determine to release (UE) context ofthe wireless device based on the context release request message fromthe base station distributed unit. In response to the context releaserequest message, the base station central unit may transmit the contextrelease command to the base station distributed unit.

In an example, small data transmission (SDT) may comprise exchange ofuser data between a wireless device and a base station while thewireless device remains in a non-connected state (e.g., idle, inactive,etc.). The amount of data exchanged in an SDT may be smaller than athreshold amount of data. The SDT may comprise one SDT of a small amountof data and/or a sequence of SDT transmissions. For example, using SDT,the wireless device and/or base station may transmit and/or receive theuser data using the control plane (e.g., control signal, RRC message,etc.). For example, using SDT, the wireless device and/or base stationmay transmit and/or receive the user data using the user plane while thewireless device remains in the non-connected state (e.g., idle,inactive, etc.). For example, using SDT, the wireless device maytransmit and/or receive the user data without completing a connectionsetup or resume procedure (accompanied by control plane signaling).

SDT may comprise any procedure for small data exchange in which smalldata exchange is performed without transitioning the wireless device toa connected state. SDT may comprise configured grant-based transmissionof small data and/or random access-based transmission of small data. Forexample, SDT may comprise transmission using preconfigured uplinkresource (PUR) and/or early data transmission (EDT). For example, inconfigured (preconfigured) grant-based transmission (e.g., transmissionusing PUR), the wireless device may be configured with a preconfiguredgrant, and the grant may be used to send small data withouttransitioning to a connected state. For example, in random access-basedtransmission (e.g., EDT), the wireless device may obtain an uplink grantvia a broadcast message (e.g., system information), dedicated signaling(e.g., wireless device-specific signaling), and/or via a random accessprocedure (e.g., based on preamble transmission) and transmits and/orreceives small data based on the uplink grant without transitioning to aconnected state.

FIG. 22 illustrates an example of updating information of a logicalchannel for small data transmission. A wireless device may storeinformation of a logical channel configured for small data transmissionin an RRC inactive state (or an RRC idle state). The information may beinformation of logical channel A (e.g., logical channel information A).For example, the wireless device may receive the information from thebase station when the wireless device is in an RRC connected state. Thewireless device may transition to an RRC inactive state (or an RRC idlestate) from the RRC connected state. The wireless device in the RRCinactive state (or the RRC idle state) may access to a base station viaa cell of the base station. The wireless device may indicate to the basestation that the wireless device intends not to transition to an RRCconnected state. For example, the wireless device may indicate intendingnot to transition to an RRC connected state based on transmitting an RRCrequest message indicating RAN-based Notification Area update (RNAupdate). For example, the wireless device may indicate intending not totransition to an RRC connected state based on transmitting a message forsmall data transmission where the message comprises at least one of: anRRC request message; (small) data; and assistance parameters indicatingsmall data transmission.

In an example of the FIG. 22 , the wireless device in the RRC inactivestate or the RRC idle state may indicate to the base station that thewireless device intends not to transition to an RRC connected state. Thebase station may intend to update the information of the logical channelconfigured for the small data transmission. The base station maytransition the wireless to an RRC connected state. For example, based onthe transition to the RRC connected state, the base station may transmitto the wireless device the updated information (e.g., information oflogical channel B or logical channel information B). Based on receivingthe updated information, the wireless device in the RRC connected statemay store the updated information. The base station may transition thewireless device to an RRC inactive state. For example, the base stationmay transition the wireless device to the RRC inactive state based ontransmitting an RRC release message. The wireless device may transitionto the RRC inactive state from the RRC connected state.

In an example of the FIG. 22 , the wireless device in an RRC inactivestate intending not to transition to an RRC connected state maytransition to the RRC connected state to update the information of thelogical channel configured for the small data transmission. The wirelessdevice in the RRC connected state may transition back to an RRC inactivestate. The transition from the RRC inactive state to the RRC connectedstate and from the RRC connected state to the RRC inactive state maycause the wireless device signal overheads for the transitioning andpower consumption due to the transitioning and time of the RRC connectedstate.

In this present disclosure, the terms configured grant (CG), configureduplink grant (CUG), and preconfigured uplink resource (PUR) may be usedinterchangeably.

In this present disclosure, transmission by a wireless device in an RRCinactive state and/or an RRC idle state (i.e., transmission by thewireless device not in the RRC connected state) may be associated withsmall data transmission (SDT) and/or a SDT procedure.

In existing technologies, a base station may transmit to a wirelessdevice information of a logical channel and/or a radio bearer (e.g., alogical channel configuration) for an RRC connected state. The basestation may send the logical channel configuration via an RRCreconfiguration message while the wireless device is in an RRC connectedstate. The wireless device may use the logical channel configuration forcommunication with the base station while the wireless device is in theRRC connected state. While the wireless device is in RRC connectedstate, the base station may configure a logical channel for small datatransmission. The logical channel configuration may be used while thewireless device is in an RRC inactive and/or RRC idle state (e.g., aftertransitioning from the RRC connected state to inactive and/or idle).Based on the logical channel configuration of the logical channel, thewireless device may perform the small data transmission (SDT) (e.g., anSDT procedure) while the wireless device is in an RRC inactive state.

In some scenarios, a base station may determine to configure a logicalchannel configuration of a logical channel to the wireless device whilethe wireless device is in the RRC inactive and/or RRC idle state (e.g.,after transitioning the wireless device from the RRC connected state).For example, the base station may determine that a previousconfiguration of one or more logical channels for a small datatransmission procedure will be updated. For example, the base stationmay determine to reconfigure the wireless device for small datatransmission based on new and/or different logical channelconfiguration. For example, the base station may need to update one ofparameters in the logical channel configuration. In existingtechnologies, the logical channel configuration is transmitted to thewireless device while the wireless device is in the RRC connected state(e.g., in an RRC reconfiguration message). If the wireless device is notin the RRC connected state, then the base station may, for example,transition the wireless device to an RRC connected state for a purposeof a logical channel configuration of the logical channel for small datatransmission. The transitioning to the RRC connected state to configurethe logical channel configuration may cause increased signalingoverhead, power consumption, and delays for small data transmission.

Example embodiments of the present disclosure are directed to anenhanced procedure for configuring a logical channel configuration of alogical channel configured for transmission in an RRC inactive state oran RRC idle state (e.g., small data transmission). Whereas existingtechnologies continue to implement the high-overhead procedure forconfiguring the logical channel configuration, example embodiments avoidtransitioning a wireless device to an RRC connected state when a basestation configures a logical channel configuration of a logical channelconfigured to the transmission in an RRC inactive state or an RRC idlestate (e.g., small data transmission).

In example embodiments of the present disclosure, the exampleembodiments leverage an RRC release procedure/message in order to moreefficiently configure the logical channel configuration of the logicalchannel configured for small data transmission. For example, a basestation may transmit the logical channel configuration of the logicalchannel configured for the small data transmission to a wireless devicevia an RRC release message. For example, a base station may transmit toa wireless device the logical channel configuration of the logicalchannel configured for the small data transmission without transitioningthe wireless device to an RRC connected state. The wireless devicereceiving the RRC release message may stay in the RRC inactive state orthe RRC idle state. Example embodiments may reduce unnecessary signalingoverhead caused by RRC signaling and/or unnecessary transitioning to anRRC connected state to reconfigure the logical channel configuration oflogical channels configured for the small data transmission.

In example embodiments of the present disclosure, the exampleembodiments leverage an RRC reconfiguration procedure/message in orderto more efficiently configure the logical channel configuration of thelogical channel configured for small data transmission. For example, abase station may transmit to a wireless device a first logical channelconfiguration of a first logical channel configured for transmission inan RRC connected state (e.g., via an RRC reconfiguration message). Basedon the first logical channel configuration, the wireless device may becapable of transmitting data of the first logical channel to a basestation while the wireless device is in the RRC connected state. Thebase station may transmit a second logical channel configuration of asecond logical channel configured to transmit in an RRC inactive stateor an RRC idle state (e.g., small data transmission) via an RRCreconfiguration message. The wireless device may not apply/configure thesecond logical channel configuration until receiving an RRC releasemessage; or transitioning to the RRC inactive state or the RRC idlestate; or determining to the transmission in the RRC inactive state orthe RRC idle state. Based on the second logical channel configuration,the wireless device may transmit data of the second logical channel to abase station. Example embodiments may reduce unnecessary signalingoverhead caused by unnecessary transitioning to an RRC connected stateto reconfigure the logical channel configuration of logical channelsconfigured for the small data transmission.

In example embodiments of the present disclosure, one or more logicalchannel configuration may comprise at least one of: one or more firstallowed parameters for first transmission in an RRC inactive state or anRRC idle state; and one or more second allowed parameters for secondtransmission in an RRC connected state. The one or more first allowedparameters may be associated with a first logical channel configured tothe transmission in an RRC inactive state or an RRC idle state. The oneor more second allowed parameters may be associated with a secondlogical channel configured to the second transmission in an RRCconnected state. For example, a first logical channel configuration ofthe one or more logical channel configuration may comprise the one ormore first allowed parameters. A second logical channel configuration ofthe one or more logical channel configuration may comprise the one ormore second allowed parameters. The first logical channel configurationmay be a logical channel configuration of the first logical channel. Thesecond logical channel configuration may be a logical channelconfiguration the second logical channel. The first logical channelconfiguration may be the second logical channel configuration. Exampleembodiments may reduce unnecessary signaling overhead caused byunnecessary transitioning to an RRC connected state to reconfigure thelogical channel configuration of logical channels configured for thesmall data transmission.

In example embodiments of the present disclosure, the one or more firstallowed parameters may comprise a first allowed configured grant (CG)list. The first allowed CG list may indicate one or more first CGs (orone or more first CG configurations) allowed to be used for transmissionof data of the first logical channel. The one or more first CGs (or oneor more first CG configurations) may be configured for the firsttransmission in the RRC inactive sate or the RRC idle state. the one ormore first allowed parameters may comprise a first allowed configuredgrant (CG) list. The second allowed CG list may indicate one or moresecond CGs (or one or more second CG configurations) allowed to be usedfor transmission of data of the second logical channel. The one or moresecond CGs (or one or more second CG configurations) may be configuredfor the second transmission in the RRC connected state. Exampleembodiments may reduce unnecessary signaling overhead caused byunnecessary transitioning to an RRC connected state to reconfigure thelogical channel configuration of logical channels configured for thesmall data transmission.

In an example, a wireless device may receive information of a firstlogical channel configured for small data transmission from a basestation while the wireless device is in an RRC inactive state or an RRCidle state. A base station may transmit the information to a wirelessdevice while the wireless device is in an RRC inactive state or an RRCidle state.

In an example, a wireless device may receive information of a firstlogical channel configured for small data transmission from a basestation via at least one of: physical layer message (e.g., DCI); or aMAC message (e.g., MAC CE); or an RRC message (e.g., an RRC releasemessage) while the wireless device is in the RRC inactive state or theRRC idle state.

In an example, a wireless device may receive from a base station a radioresource control (RRC) release message indicating transiting to an RRCinactive state. The RRC release message may comprises information of afirst logical channel configured for small data transmission.

In an example, the information of the first logical channel configuredfor the small data transmission may comprise at least one of: a logicalchannel identity of the first logical channel; and an indication thatthe first logical channel is allowed to use the small data transmission.Based on the information, a wireless device in an RRC inactive state oran RRC idle state may transmit data of the first logical channel to abase station and/or receive data of the first logical channel from thebase station. For example, based on the information, the wireless devicein the RRC inactive state or the RRC idle state may determine toinitiate small data transmission to transmit or receive the data of thefirst logical channel. Based on the information, the wireless device inthe RRC inactive state or the RRC idle state may transmit or receivedata of the first logical channel to/from a base station.

In an example, a base station may configure (pre)configured grant forsmall data transmission (e.g., PUR) to a wireless device. The firstlogical channel configured for the small data transmission may beassociated with the (pre)configured grant for the small datatransmission. The information of the first logical channel configuredfor the small data transmission may further indicate configured grantassociated with the first logical channel. The information may compriseallowed configured grant list (or allowed PUR list). The allowedconfigured grant list may indicate that data of a second logical channelis mapped to a first configured grant configuration of the allowedconfigured grant list. For example, the allowed configured grant listmay indicate that data of a second logical channel is not able to bemapped to one or more configured grant configuration of the allowedconfigured grant list. The allowed configured grant list may indicatethat data of a second logical channel is mapped to one or moreconfigured grant configuration of the allowed configured grant list. Thefirst logical channel may comprise the second logical channel. The oneor more configured grant configuration may be all configured grantconfiguration or any configured grant configuration.

For example, based on the allowed configured grant list, the wirelessdevice may determine whether to transmit data of a logical channel using(pre)configured grant for the small data transmission. For example, theallowed configured grant list may indicate that data of a second logicalchannel is mapped to a first configured grant configuration of theallowed configured grant list. Based on a logical channel of data beingthe second logical channel, the wireless device in an RRC inactive stateor an RRC idle state may determine to transmit the data of the logicalchannel using configured grant of the first logical channelconfiguration. For example, based on a logical channel of data being thesecond logical channel, the wireless device in an RRC inactive state oran RRC idle state may determine to initiate small data transmissionusing PUR (or configured grant). The wireless device in an RRC inactivestate or an RRC idle state may transmit the data of the logical channelusing configured grant of the first logical channel configuration.

In an example, the first logical channel may comprise the second logicalchannel. For example, the first logical channel may comprise a logicalchannel A and a logical channel B. The second logical channel may be thelogical channel B. The logical channel B may be mapped to the firstconfigured grant configuration of the allowed configured grant list.

In an example, the allowed configured grant list may comprise aconfigured grant configuration index of the first configured grantconfiguration. The first configured grant configuration may comprise atleast one of: a second configured grant configuration stored in thewireless device; and a third configured grant configuration in the RRCrelease message. For example, the wireless device in an RRC inactivestate or an RRC idle state may store the second configured grantconfiguration of configuration index #2. The allowed configured grantlist may comprise the configuration index #2 of the second configuredgrant configuration. The allowed configured grant list may compriseconfiguration index #3 of the third configured grant configuration notstored in the wireless device.

In an example, a base station may indicate to release the secondconfigured grant configuration. For example, the base station mayindicate configured grant configuration index and to release configuredgrant configuration of the configured grant configuration index. Thebase station may indicate information of a logical channel associatedwith the configured grant configuration. For example, the base stationmay indicate further that data of a logical channel is not able to bemapped to the configured grant configuration of the configured grantconfiguration index. The base station may indicate a logical channelidentity of the logical channel and the configured grant configurationindex. The indicating may comprise indicating via at least one of: theRRC release message; the information; or the allowed configured grantlist.

In an example, a base station may indicate to modify/update the secondconfigured grant configuration. For example, the base station mayindicate configured grant configuration index and to modify/updateconfigured grant configuration of the configured grant configurationindex. The base station may transmit parameters of the configured grantconfiguration to be modified/updated. The base station may indicateinformation of a logical channel associated with the configured grantconfiguration. For example, the base station may indicate further thatdata of a logical channel is not able to be mapped to the configuredgrant configuration of the configured grant configuration index. Thebase station may indicate a logical channel identity of the logicalchannel and the configured grant configuration index. The indicating maycomprise indicating via at least one of: the RRC release message; theinformation; or the allowed configured grant list. The indicating andthe transmitting the parameters may comprise indicating and transmittingthe parameters via single message.

In an example, a base station may indicate to setup the third configuredgrant configuration. For example, the base station may transmitconfigured grant configuration (e.g., the third configured grantconfiguration) to be setup and indicate to setup the configured grantconfiguration. The base station may indicate information of a logicalchannel associated with the configured grant configuration. For example,the base station may indicate further that data of a logical channel isable to be mapped to the configured grant configuration of theconfigured grant configuration index. The base station may indicate alogical channel identity of the logical channel and the configured grantconfiguration index. The indicating may comprise indicating via at leastone of: the RRC release message; the information; or the allowedconfigured grant list. The indicating and the transmitting theparameters may comprise indicating and transmitting the parameters viasingle message.

In an example, the third configured grant configuration may comprise PURconfiguration parameters. For example, the third configured grantconfiguration may further comprise at least one of: a configurationgrant configuration index of the third configured grant configuration;configured grant of the third grant configuration; bandwidth part of thethird configured grant configuration; a serving cell of the thirdconfigured grant configuration; and synchronization signal block (SSB)of the third configured grant configuration. For example, based on thethird configured configuration, a wireless device may transmit themessage via the bandwidth part using the configured grant. For example,based on the third configured configuration, a wireless device maytransmit the message via the serving cell using the configured grant.For example, based on the third configured configuration, a wirelessdevice may transmit a message via the SSB using the configured grant.The message may comprise at least one of: an RRC request message for thesmall data transmission; and data of the first logical channel

In an example, fourth configured grant configuration for small datatransmission may comprise allowed logical channel list indicating thatdata of a third logical channel of the allowed logical channel list ismapped to the fourth configured grant configuration. The RRC releasemessage may comprise the fourth configured grant configuration for thesmall data transmission. The information may comprise the fourthconfigured grant configuration for the small data transmission.

In an example, the information may further comprise at least one of:allowed serving cell list indicating that data of the first logicalchannel is mapped to zero or more cells in the allowed serving celllist; allowed subcarrier spacing (SCS) list indicating that data of thefirst logical channel is mapped to zero or more SCSs (numerologies) inthe allowed serving cell list; allowed physical layer (PHY) priorityindex indicating that data of the first logical channel is mapped todynamic grant indicating zero or more PHY priority index in the allowedPHY index; maximum physical uplink shared channel (PUSCH) durationindicating that data of the first logical channel is mapped to uplinkgrants of a PUSCH duration shorter than or equal to the maximum PUSCHduration; and medium access control (MAC) related parameters. Based onthe information, a wireless device may transmit a message. The messagemay comprise at least one of: an RRC request message for the small datatransmission; and data of the first logical channel. For example, basedon the information, the wireless device may transmit the message via acell of the allowed serving cell list. For example, based on theinformation, the wireless device may transmit the message via a SCS ofthe allowed SCS list.

In an example, the MAC related parameters may comprise at least one of:a channel access priority; a logical channel priority; a logical channelgroup identity; bucket size duration; bit rate multiplier; bit ratequery prohibit timer; logical channel scheduling request (SR) mask;logical channel SR delay timer applied; SR identity; and prioritized bitrate. For example, the channel access priority may indicate to be usedon uplink transmissions for operation with shared spectrum channelaccess. The SR identity may indicate the scheduling requestconfiguration applicable for the first logical channel. The logicalchannel SR delay timer applied may indicate whether to apply the delaytimer for SR transmission for this logical channel. The logical channelgroup identity may be an identity of logical channel group, which thefirst logical channel belongs to. The bit rate query prohibit timer maybe used for bit rate recommendation query. The bit rate multiplier maybe bit rate multiplier for recommended bit rate MAC CE. The logicalchannel priority may be used for logical channel prioritization. Thechannel access priority may be used on uplink transmissions foroperation with shared spectrum channel access. The bucket size durationmay indicate how much time for transmitting uplink data of a logicalchannel by using the prioritized bit rate until the bucket size isreached, value. The logical channel scheduling request SR mask may beused for controlling SR triggering when a configured uplink grant.

In an example, the wireless device may transmit the message when thewireless device is in the RRC inactive state. The wireless device maytransmit the message while the wireless device is in the RRC inactivestate. The wireless device may transmit the message during in the RRCinactive state.

In an example, the wireless device may suspend an RRC connection basedon the RRC release message. The RRC release message may comprise suspendconfiguration. The suspend configuration may indicate to suspend the RRCconnection.

In an example, the wireless device may transmit the message based oninitiating the small data transmission.

The wireless device may initiate (or determine to initiate) the smalldata transmission based on one or more conditions of the small datatransmission being met. The one or more conditions may comprise alogical channel of the data being the first logical channel. The one ormore condition may further comprise the condition for small datatransmission. the condition for small data transmission may comprise atleast one of: EDT condition; and PUR condition. For example, thewireless device may transmit the message using configured grant based onthe first logical channel being allowed to use the configured grant forthe small data transmission.

In an example, the base station may indicate to release a fourth logicalchannel configured for the small data transmission. For example, theinformation may further indicate to release a fourth logical channelconfigured for the small data transmission. For example, the informationmay indicate a logical channel identity and to release a logical channelconfiguration of the logical channel identity. The indicating maycomprise indicating via at least one of: the RRC release message; theinformation. Based on the information, the wireless device may releasethe logical channel configuration.

In an example, the base station may indicate to not to allow a fifthlogical channel to use the small data transmission. The information mayfurther indicate not to allow a fifth logical channel to use the smalldata transmission. For example, the information may indicate a logicalchannel identity and not to allow a logical channel of the logicalchannel identity for the small data transmission. The indicating maycomprise indicating via at least one of: the RRC release message; theinformation. Based on the information, the wireless device mayreconfigure the logical channel not to allow the small datatransmission.

In an example, based on the (RRC) release message indicating transitingto an RRC inactive state, the wireless device may transition to the RRCinactive state. For example, the wireless device may transition from anRRC connected state to the RRC inactive state; or from an RRC inactivestate back to the RRC inactive state; or from an RRC idle state to theRRC inactive state.

In an example, the message further may comprise assistance parametersindicating small data transmission of the first logical channel. Theassistance parameters may further indicate subsequent data of the databeing expected. The assistance parameters may comprise trafficinformation (e.g., traffic patter) of the small data transmission. Forexample, the assistance parameters may comprise buffer status report ofthe subsequent data.

In an example, the wireless device may store the information based onthe RRC release message. For example, the wireless device may store theinformation based on the RRC release message when transitioning to anRRC inactive state (or an RRC idle state). The wireless device mayrestore the stored information based on determining to initiate thesmall data transmission. For example, the wireless device in the RRCinactive state (or the RRC idle state) may restore the storedinformation based on determining to initiate the small datatransmission. The first logical channel may be further configured to beused in an RRC inactive state.

In an example, based on the information, the wireless device maytransmit a message comprising an RRC request message for the small datatransmission; and data of the first logical channel. The message may bea message for the small data transmission. For example, based on theinformation, the wireless device in the RRC inactive state or the RRCidle state may (e.g., the second RRC inactive state) may initiate thesmall data transmission. For example, based on the updated information,the wireless device may determine whether to initiate the small datatransmission. Based on the updated information, the wireless device mayselect data to transmit for the small data transmission. Based on theupdated information, the wireless device may select radio resource(e.g., uplink grant) for the small data transmission. Based on theupdated information, the wireless device may select/configure radioparameters for the small data transmission (e.g., numerologies,subcarrier spacing, priority of logical channels, MAC relatedparameters).

In an example, the small data transmission may comprise at least one of:random access control channel (RACH) based small data transmission (orEDT); and configured grant (CG) based small data transmission (or smalldata transmission using PUR).

In an example, a base station may transmit the information to a wirelessdevice via an RRC release message. For example, the base station maytransmit the RRC release message comprising the information to thewireless device. The base station may determine to reconfigure theinformation. For example, the base station may determine to reconfigurethe information when the wireless device is in an RRC connected state oran RRC inactive state or an RRC idle state. For example, the basestation may determine to reconfigure the information based on receivinga request to release or modify a radio bearer associated with the firstlogical channel from a core network entity. For example, access andmobility management function (AMF) may send a request to release a radiobearer (or PDU session) associated with the first logical channel to abase station

For example, a base station may determine to reconfigure the informationbased on determining to reconfigure configured grant configuration forthe small data transmission. Based on determining to reconfigure theconfigured grant configuration, the base station may reconfigureinformation of a logical channel associated with the reconfiguredconfigured grant configuration.

For example, the base station may determine to reconfigure theinformation based on identifying the configured grant allowed for thelogical channel being unavailable (or valid) in the base station or aserving cell of the base station. For example, a base station maydetermine to reconfigure the information based on parameters of theinformation (e.g., logical channel configuration parameters or RLCbearer configuration parameters) being invalid (or not supported). Forexample, a base station may determine to reconfigure the informationbased on the first logical channel not being supported (not beingaccepted). For example, a base station may determine to reconfigure theinformation based on radio capability associated with the first logicalchannel not being supported (not being accepted).

For example, the wireless device may receive the RRC release messageindicating transitioning to the RRC inactive state from a first basestation. The wireless device in the RRC inactive state may transmit anRRC request message (e.g., an RRC resume request message) to a secondbase station. Based on receiving the RRC request message, the secondbase station may send a retrieve (UE) context request message to thefirst base station. In response to the retrieve context request message,the first base station may send a retrieve (UE) context response messagecomprising (UE) context of the wireless device to the second basestation. Based on the retrieve context response message, the second basestation may determine at least one of: whether to accept configurationparameters (e.g., PDU session/radio bearer/logical channel or radioresource (configured grant) or radio capability) in the (UE) context; orwhich configuration parameters to be accepted/reused in the second basestation. Based on the determining, the second base station may(determine to) reconfigure the information.

In an example, the release the reconfiguring the information comprisesat least one of: releasing the first logical channel; releasing ormodifying configuration parameters associated with the first logicalchannel; releasing or modifying configured grant associated with thefirst logical channel; and releasing or modifying radio capabilityassociated with the first logical channel.

In an example, based on the determining to reconfigure the information,the base station may transmit the information: when transitioning thewireless device to an RRC inactive state or an RRC idle state; or whilethe wireless device in an RRC inactive state or an RRC idle state. Basedon the request, the base station may transmit the information via theRRC release message to the wireless device.

In an example, a wireless device in an RRC inactive state or an RRC idlestate may send an RRC request message to the base station. Based on theRRC request message, the base station may determine to release or modifythe information of the first logical channel. The base station maytransmit the information to the wireless device while in the RRCinactive state. For example, based on the request from the AMF, the basestation may send a paging message to the wireless device in an RRCinactive state (or an RRC idle state). Based on the paging message, thewireless device in the RRC inactive state may send a RRC request messageto the base station. For example, based on the request from the AMF, thebase station may wait until the wireless device sends an RRC requestmessage. For example, in response to the RRC request message, the basestation may transmit the information to the wireless device.

FIG. 23 illustrates an example of logical channel information for smalldata transmission. From a base station, a wireless device may receive anRRC release message comprising logical channel information/configurationof a logical channel configured for small data transmission (informationof a logical channel configured for small data transmission). The RRCrelease message may indicate to transition the wireless device to an RRCinactive state (or an RRC idle state). The base station may determine to(re)configure the logical channel information/configuration of a logicalchannel configured for small data transmission. Based on thedetermining, the base station may transmit the RRC release message tothe wireless device. Based on the RRC release message (or the logicalchannel information/configuration), the wireless device may store thelogical channel information/configuration of a logical channelconfigured for small data transmission. Based on the RRC releasemessage, the wireless device may transition to an RRC inactive state (oran RRC idle state). The transition may comprise at least one of:transitioning from an RRC connected state to the RRC inactive state;transitioning from an RRC inactive state back to the RRC inactive state;transitioning from an RRC idle state to the RRC inactive state.

In an example of the FIG. 23 , based on the logical channelinformation/configuration, the wireless device in the RRC inactive state(or the RRC idle state) may perform the small data transmission. Forexample, based on the logical channel information/configuration, thewireless device in the RRC inactive state may determine whether toinitiate the small data transmission. Based on the logical channelinformation/configuration, the wireless device in the RRC inactive statemay determine whether to transmit data of a logical channel to the basestation. Based on the logical channel information/configuration, thewireless device in the RRC inactive state may transmit data of a logicalchannel configured for the small data transmission.

FIG. 24 illustrates an example of logical channel information for smalldata transmission in an RRC inactive state. A wireless device in an RRCinactive state (or an RRC idle state) may store information of logicalchannel A (e.g., logical channel configuration of logical channel A)configured for small data transmission in an RRC inactive state (or anRRC idle state). The wireless device may access to a base station via acell of the base station. The wireless device may indicate intending notto transition to an RRC connected state to a base station. For example,the wireless device may indicate the intending based on transmitting anRRC request message indicating the RNA update. The RRC request messagemay comprise the RNA update as cause value. For example, the wirelessdevice may indicate the intending based on transmitting a message forsmall data transmission where the message comprises at least one of: anRRC request message; (small) data; and assistance parameters indicatingsmall data transmission.

In an example of the FIG. 23 , the base station may determine/intend toupdate the information A (a logical channel information/configuration A)of a logical channel configured for the small data transmission. Basedon the indicating, the base station may transmit an RRC release messagecomprising the updated information (e.g., the information B) to thewireless device without transitioning to an RRC connected state (whilethe wireless device is in the RRC inactive state). Based on the updatedinformation, the wireless device may update the information A with theinformation B and store the updated information. Based on the RRCrelease message, the wireless device may transition to an RRC inactivestate or an RRC idle state.

FIG. 25 illustrates an example of logical channel information for smalldata transmission in an RRC connected state. From a base station, awireless device may receive information/configuration for communicationin an RRC connected state while the wireless device is in an RRCconnected state. For example, a wireless device may receive from thebase station an RRC reconfiguration message comprising first logicalchannel information/configuration for communication in an RRC connectedstate when/while the wireless device is in an RRC connected state. Thefirst logical channel information may be information of a first logicalchannel configured for communication in an RRC connected state. Based onthe first logical channel information, the wireless device in the RRCconnected state may communicate with the base station. The communicationmay comprise at least one of: transmitting data/signal to the basestation and receiving data/signal from the base station. The wirelessdevice may receive from the base station an RRC release messagecomprising second logical channel information/configuration for smalldata transmission. For example, the base station may determine to(re)configure/modify/update second logical channelinformation/configuration for small data transmission. Based on thedetermining, the base station may transmit the RRC release message. Thesecond logical channel information may be information of a secondlogical channel configured for small data transmission. Based on thesecond logical channel information, the wireless device in an RRCinactive state may perform the small data transmission. Based on thesecond logical channel information, the wireless device in an RRCinactive state may initiate the small data transmission. Based on thesecond logical channel information, the wireless device in an RRCinactive state may transmit or receive data from a base station.

A base station may transmit an RRC release message comprisinginformation of a logical channel configured for small data transmissionto a wireless device. In existing technologies, when a base stationcomprising a base station central unit (gNB-CU) and a base stationdistributed unit (gNB-DU) transmits an RRC release message to a wirelessdevice, the base station central unit may transmit UE context releasecommand message comprising the RRC release message to the base stationdistributed unit. Based on the UE context release command message, thebase station distributed unit may release UE context of the wirelessdevice. If the wireless device in an RRC inactive state (or an RRC idlestate) transmits a message for small data transmission, the base stationdistributed unit may need the information of a logical channel toprocess the message (e.g., transmit a response to the wireless deviceand transmit data of the message to the base station central). Forexample, the wireless device in an RRC inactive state (or an RRC idlestate) transmits the message using the (pre)configured grant to the basestation. Based on receiving the message, the base station distributedunit storing configuration grant configuration for small datatransmission (e.g., PUR) may need the information of a logical channelassociated with the configured grant configuration to process themessage. The base station distributed unit may exchange signals to getthe information with the base station central unit. It may cause signaloverheads between the base station distributed unit and the base stationcentral unit. It may also cause delay to receive a response to themessage and power consumptions for the wireless device performing thesmall data transmission.

Example embodiments may support a base station central unit to transmitinformation of a logical channel configured for small data transmissionto a base station distributed unit via (UE) context release commandmessage. Based on receiving the information, the base stationdistributed unit may store the information while the wireless device isin an RRC inactive state (or an RRC idle state) and restore/use theinformation during the small data transmission. Example embodiments mayreduce the signal overheads between a base station distributed unit anda base station central unit during small data transmission. Exampleembodiments may also reduce delay and power consumptions of the wirelessdevice during small data transmission.

Example embodiments may support a base station distributed unit totransmit first information of a logical channel configured for smalldata transmission to a base station central unit via (UE) contextrelease request message. Based on receiving the first information forsmall data transmission, the base station central unit may determinesecond information of a logical channel configured for small datatransmission. In response to the context release request message, thebase station central unit may transmit the second information (orindicate confirmation for the first information) to the base stationdistributed unit. Based on receiving the second information, the basestation distributed unit may store the second information while thewireless device is in an RRC inactive state (or an RRC idle state) andrestore/use the information during the small data transmission. Exampleembodiments may reduce the signal overheads between a base stationdistributed unit and a base station central unit during small datatransmission. Example embodiments may also reduce delay and powerconsumptions of the wireless device during small data transmission.

In an example, a base station distributed unit may transmit firstinformation of a logical channel configured for small data transmissionof a wireless device to a base station central unit. A base stationdistributed unit may transmit first information of a logical channelconfigured for small data transmission to a base station central unitvia an (UE) context release request message.

In an example, based on the first information, the base station centralunit may transmit an RRC release message comprising the firstinformation to the wireless device via the base station distributedunit. For example, based on the first information, the base stationcentral unit may transmit an (UE) context release command messagecomprising the RRC release message to the base station distributed unit.Based on the first information, the base station central unit may storethe first information in context of the wireless device. Based on thecontext release command message, the base station distributed unit maytransmit the RRC release message. Based on the context release commandmessage, the base station distributed unit may store the firstinformation. The context release command message may indicate to confirmthe first information. The context release command message may indicateto store the first information.

In an example, based on the first information, the base station centralunit may update the first information. Based on the updating, the basestation central unit may generate second information of a logicalchannel configured for the small data transmission. The base stationcentral unit may store the second information in context of the wirelessdevice.

In an example, a base station central unit may transmit an RRC releasemessage comprising information to a wireless device via a base stationdistributed unit. The base station central unit may transmit an (UE)context release command message comprising an RRC release message to thebase station distributed unit. The context release command message maycomprise the information and the RRC release message. Based on thecontext release command message, the base station distributed unit maytransmit the RRC release message. Based on the context release commandmessage, the base station distributed unit may store the informationand/or configure the information. The context release command messagemay indicate to store/configure the second information.

FIG. 26 illustrates an example of logical channel information for smalldata transmission in a base station comprising CU (central unit) and DU(distributed unit). A base station central unit may transmit a (UE)context release command message comprising an RRC release message to abase station distributed unit. The base station distributed unit may notidentity/use contents of the RRC release message. The base stationcentral unit may transmit information of a logical channel configuredfor small data transmission to the base station distributed unitseparately while the base station central unit transmits an RRC releasemessage comprising the information via the context release commandmessage. For example, the context release message may comprise at leastone of: an RRC release message for a wireless device; and information ofa logical channel configured for small data transmission of the wirelessdevice. Based on the context release command message, the base stationdistributed unit may transmit/forward the RRC release message to thewireless device. Based on the context release command message, the basestation distributed unit may update context of the wireless device withthe information and/or configure the information.

In an example, the base station central unit may transmit the contextrelease command message to the base station distributed unit based ondetermining completion of the small data transmission. The base stationcentral unit may determine the completion of the small data transmissionbased on at least one of: an indication indicating the completion fromthe base station distributed unit or a core network entity (e.g., AMF orUPF); an end mark from the base station distributed unit or a corenetwork entity (e.g., AMF or UPF); assistance parameters for the smalldata transmission received from the wireless device.

In an example of the FIG. 26 , a base station distributed unit maytransmit first information of a logical channel configured for smalldata transmission to a base station central unit. For example, a basestation distributed unit may transmit the first information of a logicalchannel configured for small data transmission to a base station centralunit via a (UE) context release request message. Based on the firstinformation, the base station central unit may determine toupdate/configure information of a logical channel configured for smalldata transmission. Based on the determining, the base station centralunit may generate second information of a logical channel configured forthe small data transmission. The base station central unit may transmitthe second information via a (UE) context release command message to abase station distributed unit. Based on receiving the secondinformation, the base station distributed unit may store the secondinformation while the wireless device is in an RRC inactive state (or anRRC idle state) and restore/use the information during the small datatransmission.

In an example, the base station distributed unit may transmit thecontext release request message to the base station central unit basedon determining completion of the small data transmission. The basestation distributed unit may determine the completion of the small datatransmission based on at least one of: an indication indicating thecompletion from the base station central unit or the wireless device orcore network entity (e.g., UPF); an end mark from the base stationcentral unit or core network entity (e.g., UPF); assistance parametersfor the small data transmission received from the wireless device.

A wireless device in an RRC connected state may communicate with a basestation based on first configuration for communication in an RRCconnected state. In existing technologies, the wireless device in theRRC connected state may receive an RRC reconfiguration messagecomprising second configuration for small data transmission (e.g.,information of a logical channel configured for the small datatransmission). In existing technologies, based on receiving the RRCreconfiguration message, the wireless device in the RRC connected statemay configure the second configuration. Based on the configuring thesecond configuration, the second configuration may overwrite or replaceor remove parameters of the first configuration. The communication inthe RRC connected state based on the second configuration may causesignal overheads, delay or power consumption to the communicationbetween the wireless device and the base station. For example, based onthe second configuration, the wireless device may not transmit to dataof logical channel/radio bearer due to transmission of the data or radioresource for the transmission of the data which is allowed by the firstconfiguration but not allowed by the second configuration.

Example embodiments may reduce signal overheads, delay or powerconsumption for the communication in an RRC inactive state. Exampleembodiments may support a wireless device to perform small datatransmission in an RRC inactive state based on configuration for smalldata transmission received via an RRC reconfiguration message in an RRCconnected state.

In an example, from a base station, a wireless device in an RRCconnected state may receive an RRC reconfiguration comprising secondconfiguration for small data transmission. The second configuration mayindicate that the second configuration is for small data transmission inan RRC inactive state (or an RRC idle state). Based on receiving thesecond configuration, the wireless device may delay/postpone/deactivateto configure the second configuration (or suspend/deactivate the secondconfiguration). Based on transitioning to the RRC inactive state (or theRRC idle state), the wireless device may configure the secondconfiguration (or resume to configure the second configuration). Forexample, based on receiving an RRC release message, the wireless devicemay configure/activate the second configuration (or resume/activate toconfigure the second configuration).

In an example, the RRC reconfiguration message may comprise at least oneof: first configuration for communication in an RRC inactive state; andthe second configuration. The second configuration may compriseinformation of a logical channel configured for the small datatransmission.

A wireless device in an RRC connected state may communicate with a basestation based on first configuration for communication in an RRCconnected state. In existing technologies, the base station may transmitto the wireless device in the RRC connected state an RRC reconfigurationmessage comprising second configuration for small data transmission(e.g., information of a logical channel configured for the small datatransmission). In existing technologies, a base station central unit ofthe base station may send a HAP message comprising the RRC configurationmessage to a base station distributed unit of the base station whereinthe HAP message may comprise lower layer configuration (e.g., RLC, MAC,PHY configuration) of the second configuration. Based on the configuringthe second configuration, the second configuration may overwrite orreplace or remove parameters of the first configuration. Thecommunication in the RRC connected state based on the secondconfiguration may cause signal overheads, delay, or power consumption tothe communication between the wireless device and the base station. Forexample, based on the second configuration, the wireless device may nottransmit to data of logical channel/radio bearer due to transmission ofthe data or radio resource for the transmission of the data which isallowed by the first configuration but not allowed by the secondconfiguration.

Example embodiments may reduce signal overheads, delay, or powerconsumption for the communication in an RRC inactive state. Exampleembodiments may support a base station distributed unit to perform smalldata transmission in an RRC inactive state based on configuration forsmall data transmission received via a HAP message while the wirelessdevice is in an RRC connected state.

In an example, a base station may comprise a base station central unit(gNB-CU) and a base station distributed unit (gNB-DU). The base stationcentral unit may send a Fl application protocol (HAP) message. The HAPmessage may comprise second configuration for small data transmission(e.g., information of a logical channel configured for the small datatransmission). The F1AP message may further comprise an RRCreconfiguration message comprising first configuration for communicationin an RRC connected state. Based on the F1AP message, the base stationdistributed unit may forward the RRC reconfiguration message to thewireless device. The F1 application protocol (F1AP) message may compriseat least one of: the RRC reconfiguration message; and the secondconfiguration. The second configuration may indicate that the secondconfiguration is for small data transmission in an RRC inactive state(or an RRC idle state). The F1AP message may be an (UE) contextmodification request message; or an (UE) context setup message. In anexample, based on the second configuration, the base station distributedunit may store the second configuration. Based on receiving the secondconfiguration, the base station distributed unit maydelay/postpone/deactivate to configure the second configuration (orsuspend/deactivate the second configuration). Based on transitioning thewireless device to the RRC inactive state (or the RRC idle state), thebase station distributed unit may configure the second configuration (orresume to configure the second configuration). For example, based onreceiving UE context release message from the base station central unit,the base station distributed unit may configure/activate the secondconfiguration (or resume/activate to configure the secondconfiguration).

In an example, a base station may comprise a base station central unit(gNB-CU) and a base station distributed unit (gNB-DU). The base stationdistributed unit may send to the base station central unit secondconfiguration for small data transmission (e.g., information of alogical channel configured for the small data transmission). Based onthe second configuration, the base station central unit may transmit theRRC reconfiguration comprising the second configuration to a wirelessdevice. For example, the base station distributed unit may send thesecond configuration to the bae station central unit via at least oneof: an UE context modification required message; or an (initial) uplinkRRC transfer message.

In an example, a base station distributed unit may send to a basestation central unit a (initial) uplink RRC transfer message to transferan RRC message from a wireless device. A base station distributed unitmay send to a base station central unit an UE context modificationrequired message to modify (UE) context of a wireless device.

In an example, a base station central unit may send to a base stationdistributed unit an UE context release command message to order therelease of (UE) context of a wireless device (e.g., the UE-associatedlogical connection or candidate cells in conditional handover orconditional PSCell change). a base station distributed unit may send toan UE context release request message a base station central unit toorder/request the release of (UE) context of a wireless device.

FIG. 27 illustrates an first example of information of logical channelconfigured for small data transmission. As shown in an example 1),information of logical channel configured for small data transmissionmay comprise at least one of: a logical channel identity of a logicalchannel configured for the small data transmission; and an indicationthat the logical channel is allowed to use/perform the small datatransmission in an RRC inactive state (or an RRC idle state). As shownin an example 2), information of logical channel configured for smalldata transmission may comprises allowed logical channel small datatransmission list. The allowed logical channel small data transmissionlist may comprise a logical channel identify of at least one logicalchannel configured for the small data transmission. The allowed logicalchannel small data transmission list may indicate that the at least onelogical channel in the allowed logical channel small data transmissionlist is allowed to use/perform the small data transmission in an RRCinactive state (or an RRC idle state). For example, data of the at leastone logical channel is allowed to use/perform the small datatransmission. For example, data of the at least one logical channel isallowed to be transmitted (and/or received) in an RRC inactive state (oran RRC idle state). For example, data of the at least one logicalchannel is allowed to be transmitted (and/or received) during the smalldata transmission.

FIG. 27 illustrates an second example of information of logical channelconfigured for small data transmission. information of logical channelconfigured for small data transmission may indicate that a logicalchannel in the information is mapped to at least one configured grantconfiguration. As shown in an example 1), the information of the logicalchannel configured for the small data transmission may comprise at leastone of: a logical channel identity of the logical channel configured forthe small data transmission; and allowed configured grant small datatransmission list mapped to the logical channel. The allowed configuredgrant small data transmission list mapped to the logical channel maycomprise at least one configured grant configuration mapped to thelogical channel and allowed to be used for the small data transmissionin an RRC inactive state (or an RRC idle state). For example, theinformation may comprise at least one of: a logical channel identity Bof a logical channel ; and/or allowed configured grant small datatransmission list mapped to the logical channel. The allowed configuredgrant small data transmission list mapped to the logical channel maycomprise a configured grant configuration index (e.g., CGconfigindex #1)of the at least one configured grant configuration. The information mayindicate a logical channel of the logical channel identity (e.g., thelogical channel identity B) is allowed to use configured grantconfiguration of the allowed logical channel small data transmissionlist for the small data transmission in an RRC inactive state (or an RRCidle state).

In an example of the FIG. 27 , as shown in an example 2), information ofthe logical channel configured for the small data transmission maycomprise at least one of: a configuration index of configured grantconfiguration; a logical channel mapped to the configured grantconfiguration (or mapped to the configuration index). The configuredgrant configuration may be configured grant configuration configured forsmall data transmission. The logical channel mapped to the configuredgrant configuration may comprise at least one logical channel identity(e.g., logical channel identity B) of the logical channel. The logicalchannel mapped to the configured grant may be associated logical channellist mapped to the configured grant configuration. The associatedlogical channel list may comprise the at least one logical channelidentity (e.g., logical channel identity B) of the logical channel. Theinformation may indicate that the configured grant configuration (mappedto the logical channel) is allowed to be used for small datatransmission of the logical channel. For example, may indicate that theconfigured grant configuration (mapped to the logical channel) isallowed to be used for transmission (and/or reception) of data of thelogical channel. The logical channel may be the logical channel mappedto the configured grant configuration or a logical channel in theassociated logical channel list.

In an example, a wireless device may receive from a base station a radioresource control (RRC) release message indicating transiting to an RRCinactive state, where the RRC release message may comprise informationof a first logical channel configured for small data transmission. Thewireless device may transmit, based on the information, a messagecomprising an RRC request message for the small data transmission; anddata of the first logical channel.

In an example, the information may comprise at least one of: a logicalchannel identity of the first logical channel; and an indication thatthe first logical channel is allowed to use the small data transmission.

In an example, the small data transmission may comprise at least one of:random access control channel (RACH) based small data transmission (orEDT); and configured grant (CG) based small data transmission (or smalldata transmission using PUR).

In an example, the information may further comprise allowed configuredgrant list indicating that data of a second logical channel is mapped toa first configured grant configuration of the allowed configured grantlist.

In an example, the first logical channel may comprise the second logicalchannel.

In an example, the allowed configured grant list may comprise aconfigured grant configuration index of the first configured grantconfiguration.

In an example, the first configured grant configuration may comprise atleast one of: a second configured grant configuration stored in thewireless device; and a third configured grant configuration in the RRCrelease message.

In an example, the third configured grant configuration may comprises atleast one of: a configuration grant configuration index of the thirdconfigured grant configuration; configured grant of the third grantconfiguration; bandwidth part of the third configured grantconfiguration; a serving cell of the third configured grantconfiguration; and synchronization signal block (SSB) of the thirdconfigured grant configuration.

In an example, fourth configured grant configuration for the small datatransmission may comprise allowed logical channel list indicating thatdata of a third logical channel of the allowed logical channel list ismapped to the fourth configured grant configuration. The RRC releasemessage may comprise the fourth configured grant configuration for thesmall data transmission.

In an example, the information may further comprise at least one of:allowed serving cell list indicating that data of the first logicalchannel is mapped to one or more cells in the allowed serving cell list;allowed subcarrier spacing (SCS) list indicating that data of the firstlogical channel is mapped to one or more SCSs (numerologies) in theallowed serving cell list; allowed physical layer (PHY) priority indexindicating that data of the first logical channel is mapped to dynamicgrant indicating one or more PHY priority index in the allowed PHYindex; maximum physical uplink shared channel (PUSCH) durationindicating that data of the first logical channel is mapped to uplinkgrants of a PUSCH duration shorter than or equal to the maximum PUSCHduration; and medium access control (MAC) related parameters.

In an example, the MAC related parameters may comprise at least one of:a channel access priority; a logical channel priority; a logical channelgroup identity; bucket size duration; bit rate multiplier; bit ratequery prohibit timer; logical channel scheduling request (SR) mask;logical channel SR delay timer applied; SR identity; and prioritized bitrate.

In an example, transmitting the message may comprise transmitting themessage when the wireless device is in the RRC inactive state.

In an example, the wireless device may suspend, based on the RRC releasemessage, an RRC connection.

In an example, the transmitting the message comprise transmitting themessage based on initiating the small data transmission.

In an example, the initiating the small data transmission may compriseinitiating the small data transmission based on one or more conditionsof the small data transmission being met.

In an example, the one or more conditions may comprise a logical channelof the data being the first logical channel.

In an example, the transmitting the message may comprise transmittingthe message using configured grant based on the first logical channelbeing allowed to use the configured grant for the small datatransmission.

In an example, the information may indicate at least one of: releasing afourth logical channel; and not to allow a fifth logical channel to usethe small data transmission.

In an example, the RRC release message may indicate that the wirelessdevice is not allowed to use a fifth configured grant configuration forthe small data transmission.

In an example, the transitioning to the RRC inactive state may comprisesat least one of: transitioning the wireless device in an RRC connectedstate to the RRC inactive state; and transitioning the wireless devicein the RRC inactive state back to the RRC inactive state.

In an example, the wireless device may be in an RRC inactive state.

In an example, the RRC request message may be a RRC resume requestmessage.

In an example, the message may further comprise assistance parametersindicating small data transmission of the first logical channel.

In an example, the small data transmission may comprise transmission andreception of one or more data without transitioning to an RRC connectedstate.

In an example, the transmission and the reception may comprisetransmission and reception via at least one of: user plane; or controlplane.

In an example, the first logical channel may be associated with a dataradio bearer.

In an example, the transmitting the message may comprise transmitting:the RRC request message via common control channel (CCCH); and the datavia dedicated traffic channel (DTCH)

In an example, the information may comprise a logical channelconfiguration.

In an example, the information may comprise at least one of: a logicalchannel configuration; radio link control (RLC) bearer configuration;and radio bearer configuration.

In an example, the wireless device may store the information based onthe RRC release message.

In an example, the wireless device may restore, based on determining toinitiate the small data transmission, the stored information.

In an example, the first logical channel may be further configured to beused in an RRC inactive state.

In an example, the receiving the RRC release message may comprisereceiving the RRC release message in at least one of : an RRC connectedstate; an RRC inactive state; or an RRC idle state.

In an example, the transmitting the message further may comprisetransmitting the message in at least one of:

an RRC inactive state; or an RRC idle state.

In an example, a base station may transmit to a wireless device a radioresource control (RRC) release message indicating transiting to an RRCinactive state, where the RRC release message comprises information of afirst logical channel configured for small data transmission. The basestation may receive, based on the information, a message for the smalldata transmission comprising at least one of: an RRC request message forthe small data transmission; and data of the first logical channel.

In an example, the base station may determine to reconfigure theinformation. The transmitting may comprise transmitting based on thedetermining.

In an example, the determining may comprise determining based on atleast one of: receiving, from a core network entity, a request torelease or modify a radio bearer associated with the first logicalchannel; identifying configured grant allowed for the first logicalchannel being unavailable; identifying configuration parameters of thefirst logical channel being invalid; identifying the first logicalchannel not being supported; and identifying radio capability associatedwith the first logical channel not being supported.

In an example, the determining may comprise determining by a second basestation.

In an example, the core network entity may comprise at least one of:access and mobility management function (AMF); user plane function(UPF); and session management function (AFM)

In an example, the receiving may comprise receiving by a second basestation.

In an example, the reconfiguring the information may comprise at leastone of: releasing the first logical channel; releasing or modifyingconfiguration parameters associated with the first logical channel;releasing or modifying configured grant associated with the firstlogical channel; and releasing or modifying radio capability associatedwith the first logical channel.

In an example, a base station central unit may transmit to a basestation distributed unit a command to release contexts of a wirelessdevice wherein the command comprises second information of a logicalchannel configured for small data transmission. From the wirelessdevice, the base station central unit may receive, based on the secondinformation, a message comprising at least one of: an RRC requestmessage for the small data transmission; and assistance parametersindicating small data transmission of the at least one logical channel.

In an example, the command may comprise a radio resource control (RRC)release message indicating transition of the wireless device from an RRCconnected state to an RRC inactive state (or an RRC idle state).

In an example, the RRC release message comprises the second information.

In an example, the transmitting the command may comprise transmittingthe command in response to receiving, from the base station distributedunit, a request to release the context of the wireless device

In an example, the request may comprise first information of the logicalchannel configured for small data transmission. The base station centralunit may generate, based on the first information, the secondinformation.

In an example, the receiving the message may comprise receiving themessage when the wireless device is in an RRC inactive state or an RRCidle state.

In an example, a base station distributed unit may receive, from a basestation central unit, a command to release contexts of a wireless devicewherein the command comprises second information of a logical channelconfigured for small data transmission. From the wireless device, thebase station distributed unit may receive, based on the secondinformation, a message comprising at least one of: an RRC requestmessage for the small data transmission; and assistance parametersindicating small data transmission of the at least one logical channel.

In an example, the receiving the command may comprise receiving thecommand in response to transmitting a request to release the context ofthe wireless device.

In an example, the request may comprise first information of the logicalchannel configured for small data transmission.

In an example, the base station distributed unit may transmit/forward,to the base station central unit, the message.

In an example, the base station distributed unit may store, based onreceiving the second information, the second information.

In an example, the storing the second information may comprises storingthe second information while the wireless device is in an RRC inactivestate or an RRC idle state.

What is claimed is:
 1. A method comprising: transmitting, by a basestation to a wireless device, a radio resource control (RRC)reconfiguration message comprising a first logical channel configurationfor transmission of data of a first logical channel in an RRC connectedstate; transmitting, by the base station to the wireless device, an RRCrelease message comprising a second logical channel configuration fortransmission of data of a second logical channel in an RRC inactivestate or an RRC idle state, wherein the second logical channelconfiguration comprises an allowed configured grant list indicating thatthe data of the second logical channel is mapped to a configured grantconfiguration, of a configured grant, for transmission in the RRCinactive state or the RRC idle state; and receiving, by the base stationfrom the wireless device, the data of the second logical channel.
 2. Themethod of claim 1, wherein the configured grant configuration isincluded in the RRC release message.
 3. The method of claim 1, whereinthe allowed configured grant list comprises an index of the configuredgrant configuration, of the configured grant, as an indication that thesecond logical channel is allowed to use the configured grant.
 4. Themethod of claim 1, further comprising transitioning, by the basestation, based on transmitting the RRC release message to the wirelessdevice, the wireless device to the RRC inactive state or the RRC idlestate.
 5. The method of claim 1, wherein the receiving is from thewireless device in the RRC inactive state or the RRC idle state using asmall data transmission procedure.
 6. The method of claim 1, wherein theconfigured grant configuration comprises at least one of: aconfiguration grant configuration index of the configured grantconfiguration; a configured grant of the configured grant configuration;a bandwidth part of the configured grant configuration; a serving cellof the configured grant configuration; and a synchronization signalblock (SSB) of the configured grant configuration.
 7. The method ofclaim 1, wherein the second logical channel configuration comprises atleast one of: an allowed subcarrier spacing (SCS) list indicating thatthe data of the second logical channel is mapped to one or more SCSs; anallowed physical layer (PHY) priority index indicating that the data ofthe second logical channel is mapped to one or more dynamic grantsindicating one or more PHY priorities; or a maximum physical uplinkshared channel (PUSCH) duration indicating that the data is mapped touplink grants of a PUSCH duration shorter than or equal to the maximumPUSCH duration.
 8. A base station comprising: one or more processors;and memory storing instructions that, when executed by the one or moreprocessors, cause the base station to: transmit, to a wireless device, aradio resource control (RRC) reconfiguration message comprising a firstlogical channel configuration for transmission of data of a firstlogical channel in an RRC connected state; transmit, to the wirelessdevice, an RRC release message comprising a second logical channelconfiguration for transmission of data of a second logical channel in anRRC inactive state or an RRC idle state, wherein the second logicalchannel configuration comprises an allowed configured grant listindicating that the data of the second logical channel is mapped to aconfigured grant configuration, of a configured grant, for transmissionin the RRC inactive state or the RRC idle state; and receive, from thewireless device, the data of the second logical channel.
 9. The basestation of claim 8, wherein the configured grant configuration isincluded in the RRC release message.
 10. The base station of claim 8,wherein the allowed configured grant list comprises an index of theconfigured grant configuration, of the configured grant, as anindication that the second logical channel is allowed to use theconfigured grant.
 11. The base station of claim 8, wherein theinstructions cause the base station to transition, based on transmittingthe RRC release message to the wireless device, the wireless device tothe RRC inactive state or the RRC idle state.
 12. The base station ofclaim 8, wherein the receiving is from the wireless device in the RRCinactive state or the RRC idle state using a small data transmissionprocedure.
 13. The base station of claim 8, wherein the configured grantconfiguration comprises at least one of: a configuration grantconfiguration index of the configured grant configuration; a configuredgrant of the configured grant configuration; a bandwidth part of theconfigured grant configuration; a serving cell of the configured grantconfiguration; and a synchronization signal block (SSB) of theconfigured grant configuration.
 14. The base station of claim 8, whereinthe second logical channel configuration comprises at least one of: anallowed subcarrier spacing (SCS) list indicating that the data of thesecond logical channel is mapped to one or more SCSs; an allowedphysical layer (PHY) priority index indicating that the data of thesecond logical channel is mapped to one or more dynamic grantsindicating one or more PHY priorities; or a maximum physical uplinkshared channel (PUSCH) duration indicating that the data is mapped touplink grants of a PUSCH duration shorter than or equal to the maximumPUSCH duration.
 15. A non-transitory computer-readable mediumcomprising: one or more processors; and memory storing instructionsthat, when executed by the one or more processors, cause the one or moreprocessors to: transmit, to a wireless device, a radio resource control(RRC) reconfiguration message comprising a first logical channelconfiguration for transmission of data of a first logical channel in anRRC connected state; transmit, to the wireless device, an RRC releasemessage comprising a second logical channel configuration fortransmission of data of a second logical channel in an RRC inactivestate or an RRC idle state, wherein the second logical channelconfiguration comprises an allowed configured grant list indicating thatthe data of the second logical channel is mapped to a configured grantconfiguration, of a configured grant, for transmission in the RRCinactive state or the RRC idle state; and receive, from the wirelessdevice, the data of the second logical channel.
 16. The base station ofclaim 8, wherein the configured grant configuration is included in theRRC release message.
 17. The base station of claim 8, wherein theallowed configured grant list comprises an index of the configured grantconfiguration, of the configured grant, as an indication that the secondlogical channel is allowed to use the configured grant.
 18. The basestation of claim 8, wherein the instructions cause the one or moreprocessors to transition, based on transmitting the RRC release messageto the wireless device, the wireless device to the RRC inactive state orthe RRC idle state.
 19. The base station of claim 8, wherein thereceiving is from the wireless device in the RRC inactive state or theRRC idle state using a small data transmission procedure.
 20. The basestation of claim 8, wherein the configured grant configuration comprisesat least one of: a configuration grant configuration index of theconfigured grant configuration; a configured grant of the configuredgrant configuration; a bandwidth part of the configured grantconfiguration; a serving cell of the configured grant configuration; anda synchronization signal block (SSB) of the configured grantconfiguration.